Reporting quality of clinical practice guidelines on head and neck cancer: a systematic review

Introduction

Head and neck cancer (HNC) is a highly heterogeneous disease with distinct histopathological characteristics. Together with the different anatomical locations of origin, these lead to different manifestations and outcomes (1). About 931,931 new cases of HNC occurred and 467,125 patients died because of HNC worldwide in 2020. The majority of them were squamous cell carcinomas which originated from the oral cavity, oropharynx, nasopharynx, larynx, and hypopharynx, and often related to the tobacco and alcohol misuse (2). Its incidence varies greatly in different regions around the world. In recent years, there have been rapid advances in immunotherapy of HNC. Along with this, improvements in standard therapy have enhanced preservation of function and reduced morbidity and mortality (3). In general, patients with early-stage HNC are treated with surgery or radiotherapy as a single modality and have favorable outcomes. However, locally advanced diseases at diagnosis usually require multi-modality therapies. Palliative chemotherapy is the treatment for most recurrent and/or metastatic HNC. Immune checkpoint inhibitors have been rapidly developed in the treatment of advanced HNC in recent years. Many clinical trials are exploring the possibility of combining immunotherapy with other treatment modalities. In addition to the diversity of treatments, the diagnosis, management, and prognosis of HNC also have many indicators. Previous studies have shown that increased infiltration of CD3⁺, CD8⁺, CD4⁺ and Foxp3⁺ tumor-infiltrating lymphocytes (TILs) are associated with better prognosis in HNC. High CD4⁺ and CD8⁺ TIL were significantly associated with improved OS in oropharyngeal cancer, and high CD8⁺ was significantly associated with improved OS in hypopharyngeal cancer (4,5). Therefore, clinical practice guidelines (CPGs) are used commonly by physicians with gathering a large number of clinical recommendations based on systematic reviews of the literature (6). With rating the quality of evidence and strength of recommendations, CPGs aim to interpret and consolidate evidence from the expansive clinical research literature to establish standards for clinical practice. CPGs have been increasingly used over the past decade worldwide. However, the reporting qualities of CPGs are not satisfactory enough (7,8). In the past, most guidelines were evaluated by the Appraisal of Guidelines, Research and Evaluation (AGREE) II, a validated tool for the systematic appraisal of CPG methodological development and quality (9). However, it is gradually replaced by the Reporting Items for Practice Guidelines in Healthcare (RIGHT) checklist because of the limited value in evaluating some specific types of guidelines (10). RIGHT checklist was developed and launched by a group of international experts with multidisciplinary intellectual background in 2016. And now it has been widely recognized as a standard in the development and evaluation of guidelines. In some recently published studies, some researchers have evaluated guidelines for other types of cancer through the RIGHT checklist. As research progresses and advances, the development of oncology guidelines will become more standardized (11-14). To evaluate the reporting quality of CPGs on HNC published between 2018 and 2021, we analyzed all items reported in guidelines by using the RIGHT checklist. By means of this analysis, we hope our study can not only offer users deeper understanding of CPGs, but also provide objective suggestions for the later development of guidelines. We present the following article in accordance with the PRISMA reporting checklist (available at https://tcr.amegroups.com/article/view/10.21037/tcr-22-52/rc).

Methods

Literature search

We systematically searched Medline (via PubMed), Wan Fang Database and Chinese National Knowledge Infrastructure (CNKI) for CPGs on HNC. In addition to literature databases, guidelines also were developed and published by oncological organizations or government public health agencies. So, the following websites were added to our search scope, such as World Health Organization (WHO), National Comprehensive Cancer Network (NCCN), Guidelines International Network (GIN), Scottish Intercollegiate Guidelines Network (SIGN), the National Institute for Health and Care Excellence (NICE), the European Society for Medical Oncology (ESMO), the American Society of Clinical Oncology (ASCO) and the Chinese Society of Clinical Oncology (CSCO). The search terms for PubMed included Head and Neck Neoplasms [MeSH], cancer*, carcinoma*, neoplasm*, tumour*, tumor*, and malignant*, mouth, nasopharyn*, oropharyn*, hypopharyn*, laryn*, oral, salivary gland, Guideline, Practice Guideline, guideline*, guidance* and recommendation*. We adjusted the format when we were searching through different databases and ended up with a total of 576 records. The search strategies were presented in detail in the Appendix 1.

Selection criteria of guidelines

We limited the publication time from January 2018 to July 2021. And the language of publication should be Chinese or English. If one CPG was updated, we only chose the latest version. The topic was restrict to HNC. Articles of guidelines about other cancers, non-guidelines, expert consensus in Chinese, interpretation or translation versions of guidelines, or protocols of the development would be excluded. Seven guidelines from the Oral Cancer Task Force (OCTF) focused on the same topic of HNC with different perspectives. We integrated and considered them as an independent guideline for higher efficiency.

Guideline selection, information entry and data extraction

We aggregated all guidelines searched through above procedures to move on the study conveniently. The first-time screening needs comprehensive understanding of titles and abstracts. Two investigators (Jiabao Hou and Xuan Wu) completed this procedure independently. Then they verified the identified guidelines to conduct next screening. This part of guidelines would be obtained for full details. We decided whether to include one guideline through the careful reading of the full texts. If one article met the inclusion criteria of our study, we would take it into consideration. Disagreement would be resolved by discussion or further recommendations from an independent expert (Qiming Wang). And next we enriched the RIGHT checklist by reading full texts again. Reporting information of items was inputted and original data was extracted by investigators independently. The required contents consist of different aspects in the guideline including title, year of publication, journal or website of publication, developer, country or region, development procedures, fundings and interests. All data would be checked and verified.

Reporting quality evaluation of guidelines

RIGHT checklist was used in the whole evaluation of guidelines. It includes 7 domains and 22 items. “Basic information” refers to the key content, such as title, year of publication and so on. “Background” includes specialized information. “Evidence” answers the question that what kind of literature did the guideline based on. “Recommendations” has the specific information of recommendations in the guidelines. “Review and quality assurance” includes the process of quality control. “Funding and declaration and management of interests” and “Other information” are also important ingredients (10). There are three statements of each item: “Reported”, “Not reported” or “Not applicable”. When the relevant information was provided in the guidelines, we regarded this item was “Reported”. When the relevant information was not shown, it was marked as “Not reported”. If the item did not apply for a certain guideline, that was “Not applicable”.

Like the steps above, quality assessment of each guideline was conducted by researchers in an independent way. If disagreements arose, they would be resolved by discussion or asking for recommendations from an expert adjudicator (Qiming Wang). The details of reporting quality were presented in the Appendix 1.

Statistical analysis

Every guideline reported different items, the overall reporting rate means that how many items reported in one guideline. Besides the differences among guidelines, we also showed the differences among items and domains. We used SPSS V.26.0. to calculate and analyze overall reporting rate.

Results

Identification of specific guidelines

We searched 576 articles, of which 568 were from electronic databases and 8 were from guideline-related websites, oncology organizations, or other sources. Seven duplicate records were removed. After reviewing the remaining 569 records for titles and abstracts, we excluded 522 records because they were not guidelines or were not last versions.

After full text access and reading of the 47 records which were remained after re-screening, we finally included 27 guidelines. Seven guidelines developed by the Oral Cancer Task Force (India) were combined as a series. So there were 21 reports included after combining the guideline series (Figure 1).

Figure 1 Flowchart of systematic search. CPG, clinical practice guideline; HNC, head and neck cancer.

Characteristics of included guidelines

The detailed features of each guideline were shown in Table 1. One guideline was published in 2018, four in 2019, six in 2020, and ten in 2021. Seven guidelines had reporting rates greater than or equal to 60.0%, twelve guidelines had reporting rates between 30.0% and 60.0%, and only two had reporting rates less than 30.0%. Eighteen guidelines were published in journals, and three were published on websites. Of these 21 guidelines, three were developed by China, four were developed by European multidisciplinary panel of experts, two were developed by France. And one from India, two from Spain, one from the United Kingdom, and five from the United States, leaving three from international collaborations.

General evaluation of reporting quality

The mean value of the reporting rates for these seven domains ranged from 26.2% to 75.4%, with the highest reporting rate for “Basic information” at 75.4% and the lowest reporting rate for “Funding and declaration and management of interests” at 26.2%. The remaining five domains were “Background”, “Recommendations”, “Other information”, “Evidence” and “Review and quality assurance”. Their reporting rates were 63.1%, 55.1%, 50.8%, 42.9%, and 42.9%, respectively (Figure 2). In the domain of basic information, all guidelines reported “Abbreviations and acronyms”. Sub-items (1a ,1c and 4) had relatively higher reporting rates that were above 90%. As for the background, all guidelines described the primary population that was addressed by the recommendations. However, only one guideline described the suitable application situations. The reporting rates for the remaining sub-items (5, 6, 8a, 9a and 9b) were 71.4%, 76.2%, 47.6%, 52.4% and 66.7%, respectively. In the domain “Evidence”, 61.9% of guidelines indicated that they were based on systematic reviews. The reporting rate of “Assessment of the certainty of the body of evidence” was 66.7%. Ten guidelines described the health questions on which the recommendations were based, yet only three of these described the methodology for outcome selection and classification.

Figure 2 Mean reporting rates of the RIGHT checklist sub-items by domain. RIGHT, Reporting Items for Practice Guidelines in Healthcare.

In the domain “Recommendations”, 85.7% of guidelines provided clear, precise, and actionable recommendations. The rest of sub-items (14a, 14b, 14c and 15) had reporting rates less than 50%.

The reporting rate of “Review and quality assurance” was 42.9%. None of the guidelines reported “Funding sources and roles of the funder”. The reporting rates for the remaining sub-items (19a, 19b, 20, 21 and 22) were 85.7%, 19.0%, 57.1%, 42.9% and 52.4%, respectively (Figure 3).

Figure 3 Reporting compliance to each sub-item of the RIGHT checklist in the included guidelines (The descriptions of each sub-item are shown in http://www.right-statement.org/home/extensions). RIGHT, Reporting Items for Practice Guidelines in Healthcare.

Subgroup analysis of reporting quality

The reporting rates of guidelines published from 2018 to 2021 were 42.9%, 70.5%, 51.0% and 54%, respectively. The reporting rate of guidelines published in English was slightly higher than that published in Chinese. Among those published in English, five guidelines from the United States had the highest average reporting rate. Reporting rates of guidelines from Europe and international multidisciplinary panel of experts are 48.9% and 55.2%, respectively. However, the reporting rate for Asian countries, including China and India, was only 47.1%.

Discussion

HNC is a highly heterogeneous group of cancers, which originates mainly in the oral cavity, nasopharynx, larynx, and salivary glands. In China, nasopharyngeal cancer is the most common, and the high incidence area is Guangdong province, which is related to Epstein-Barr virus (EBV) and genetic factors. While oral cancer is highly prevalent in Hunan province and is related to areca nut chewing (42). Most patients were already at an advanced stage when diagnosed, resulting in poor treatment outcomes and limited functional recovery. Moreover, the level and quality of medical services vary worldwide. It is of great importance to use more effective, standardized, and transparent methods to develop guidelines.

For a high-quality guideline, the process of its development should include discussions among multidisciplinary experts. Moreover, clear recommendations are essential. These criteria are all reflected in the RIGHT checklists. Only by following such guidelines can clinicians and health professionals play a greater role in the diagnosis, treatment, and management of disease. Therefore, we used RIGHT checklists to objectively evaluate the reporting quality of included guidelines, hoping to help clinicians make the better decisions and to draw the attention of guideline developers.

This is the first evaluation of HNC guidelines based primarily on the RIGHT checklists. Overall, the reporting rate for guidelines was moderate. Of the seven reporting domains, “Basic information” has the highest reporting rate. All guides reported “Abbreviations and acronyms (3)”. However, only 57.1% of the guidelines reported “Executive summary (2)”. Due to the numerous ways to classify and treat head and neck tumors, providing a clear and concise summary of recommendations is easy to use clinically. This makes it very easy for clinicians to find the focus from the many guidelines entries and apply the recommendations. The reporting rate for the remaining sub-items (1a ,1c and 4) was above 90% (Figure 3). The lowest reporting rate in this area was “The year of publication of the guideline (1b)”, at only 19%. This may be related to the frequency of updates by the guideline development agencies. Of these, all 3 guidelines from China reported this entry, and 2 were updated annually.

The information of background includes brief description of the health problems, aims of the guideline and specific objectives, end-users and settings, target populations and guideline development groups. The reporting rate in it varies widely. All guidelines describe the primary populations which were applicable with certain recommendations. However, only one guideline describes the suitable application situations, 47.6% of the guidelines reported intended primary users. A complete guideline should include the disease and the primary target population. All the guidelines we included met this criterion. With continued advances in radiotherapy and surgical techniques, patients undergo surgery for better organ function preservation. In addition, different populations have different levels of acceptance of post-operative aesthetics. Therefore, taking subgroup populations into consideration is also important. The reporting rate for the remaining sub-items ranged from 50% to 90%.

The information of evidence includes systematic reviews, assessment of the certainty of the body of evidence. High-quality evidence will make guidelines convincing. In the domain “Evidence”, 61.9% of guidelines indicated that they were based on systematic reviews. And 66.7% of guidelines describe the approach used to assess the certainty of evidence. Ten guidelines describe the key questions on which the recommendations were based, yet only three of these describe the methodology for outcome selection and classification. The reason may be that guideline developers caring too much about survival time, while ignoring the adverse effects of drugs, how treatments affect patients’ quality of life and mental health, etc. There are often many controversies in the diagnosis and treatment of HNC. Providing the search strategies and the selection criteria, and describing how the risk of bias was evaluated, would make guideline users treat disputes in a rational way.

The information of recommendations includes explanation for recommendations, evidence to decision processes. Most of the guidelines provided clear, precise, and actionable recommendations. 81% of guidelines indicated the strength of recommendations, the quality of the evidence supporting the recommendation, and separate recommendations for special subgroups. As for explanation for recommendations and evidence to decision processes, the reporting rate for these sub-items is less than 50%. 42.9% of the guidelines reported that the draft guideline underwent independent review and quality assurance process. In forming recommendations, only a few developers considered the preferences and values of the target population, cost and resource utilization, and factors such as fairness and feasibility. This was not only because of the difficulty of collecting this information, but also because of the lack of awareness among developers.

As for the domain of “Funding, declaration and management of interest”, none of guidelines present the certain sources of funding and the role of funders in the different phases of guideline development. One reason for this may be that funders did not influence the development of the guidelines, or it may be that their roles were consistent across the phases. 85.7% of guidelines describe whether they had conflicts of interest for authors to develop recommendations.

Regarding “Other information”, 57.1% of guidelines describe the efficient way for readers to obtain the guidelines and relative documents. 42.9% of guidelines provide suggestions for the later researches. This may be due to the fact that guideline developers were not aware of the discrepancy between current practice and research evidence. The exploration of clinical trials in HNC is rapidly evolving. Guideline developers should describe the gaps between practice and clinical research and provide appropriate advice for future research with foresight.

Strengthens and limitations

This is the first article to evaluate the HNC guidelines using the RIGHT checklist. Our investigators developed a rigorous search strategy, carefully filled in all guideline reporting items, and analyzed the reporting rates with appropriate statistical methods. As the last item in the RIGHT checklist points out: all limitations of the guideline development process should be presented, our study is not perfect in all aspects. First, our inclusion and exclusion criteria could not meet the requirements of all guideline developers because of the different definitions of HNC in different countries and regions. Second, we only included guidelines written in English and Chinese, guidelines in other languages were not included.

Conclusions

We evaluated the HNC guidelines by using the RIGHT checklist and found differences in reporting rates across domains. Most guidelines reported basic information but under-reported funding and evidence. We hope that guideline developers could not only focus on the content, but also take more concern about reporting quality.

Acknowledgments

The authors appreciate the academic support from the AME Reporting Guideline Collaborative Group.

Funding: This work was supported by the National Natural Science Foundation of China (No. 81872204), ZHONGYUAN QIANREN JIHUA (No. ZYQR201912118) and Leading Talent Cultivation Project of Henan Health Science and Technology Innovation Talents (No. YXKC2020009).

Footnote

Reporting Checklist: The authors have completed the PRISMA reporting checklist. Available at https://tcr.amegroups.com/article/view/10.21037/tcr-22-52/rc

Peer Review File: Available at https://tcr.amegroups.com/article/view/10.21037/tcr-22-52/prf

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://tcr.amegroups.com/article/view/10.21037/tcr-22-52/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

References

1. Chow LQM. Head and Neck Cancer. N Engl J Med 2020;382:60-72. [Crossref] [PubMed]
2. Sung H, Ferlay J, Siegel RL, et al. Global Cancer Statistics 2020: GLOBOCAN Estimates of Incidence and Mortality Worldwide for 36 Cancers in 185 Countries. CA Cancer J Clin 2021;71:209-49. [Crossref] [PubMed]
3. Carlisle JW, Steuer CE, Owonikoko TK, et al. An update on the immune landscape in lung and head and neck cancers. CA Cancer J Clin 2020;70:505-17. [Crossref] [PubMed]
4. de Ruiter EJ, Ooft ML, Devriese LA, et al. The prognostic role of tumor infiltrating T-lymphocytes in squamous cell carcinoma of the head and neck: A systematic review and meta-analysis. Oncoimmunology 2017;6:e1356148. [Crossref] [PubMed]
5. Muzaffar J, Bari S, Kirtane K, et al. Recent Advances and Future Directions in Clinical Management of Head and Neck Squamous Cell Carcinoma. Cancers (Basel) 2021;13:338. [Crossref] [PubMed]
6. Shekelle PG. Clinical Practice Guidelines: What's Next? JAMA 2018;320:757-8. [Crossref] [PubMed]
7. Grilli R, Magrini N, Penna A, et al. Practice guidelines developed by specialty societies: the need for a critical appraisal. Lancet 2000;355:103-6. [Crossref] [PubMed]
8. Xiao Y, Jiang L, Tong Y, et al. Evaluation of the quality of guidelines for assisted reproductive technology using the RIGHT checklist: A cross-sectional study. Eur J Obstet Gynecol Reprod Biol 2019;241:42-8. [Crossref] [PubMed]
9. Brouwers MC, Kho ME, Browman GP, et al. AGREE II: advancing guideline development, reporting and evaluation in health care. CMAJ 2010;182:E839-42. [Crossref] [PubMed]
10. Chen Y, Yang K, Marušic A, et al. A Reporting Tool for Practice Guidelines in Health Care: The RIGHT Statement. Ann Intern Med 2017;166:128-32. [Crossref] [PubMed]
11. Chen H, Tao M, Li D, et al. An evaluation of the reporting quality in clinical practice guidelines for hepatocellular carcinoma using the RIGHT checklist. Ann Transl Med 2021;9:1004. [Crossref] [PubMed]
12. Han J, Tao M, Wu X, et al. Reporting quality of practice guidelines on colorectal cancer: evaluation using the RIGHT reporting checklist. Ann Transl Med 2021;9:1175. [Crossref] [PubMed]
13. Wu X, Li D, Chen H, et al. Evaluation of the reporting quality of guidelines for gastric cancer using the RIGHT checklist. Ann Transl Med 2021;9:1003. [Crossref] [PubMed]
14. Zhou H, Chen H, Cheng C, et al. A quality evaluation of the clinical practice guidelines on breast cancer using the RIGHT checklist. Ann Transl Med 2021;9:1174. [Crossref] [PubMed]
15. Chen YP, Ismaila N, Chua MLK, et al. Chemotherapy in Combination With Radiotherapy for Definitive-Intent Treatment of Stage II-IVA Nasopharyngeal Carcinoma: CSCO and ASCO Guideline. J Clin Oncol 2021;39:840-59. [Crossref] [PubMed]
16. Carsuzaa F, Gorphe P, Vergez S, et al. Consensus on resectability in N3 head and neck squamous cell carcinomas: GETTEC recommendations. Oral Oncol 2020;106:104733. [Crossref] [PubMed]
17. Maghami E, Ismaila N, Alvarez A, et al. Diagnosis and Management of Squamous Cell Carcinoma of Unknown Primary in the Head and Neck: ASCO Guideline. J Clin Oncol 2020;38:2570-96. [Crossref] [PubMed]
18. Cabrera Rodríguez J, Cacicedo J, Giralt J, et al. GEORCC recommendations on target volumes in radiotherapy for Head Neck Cancer of Unkown Primary. Crit Rev Oncol Hematol 2018;130:51-9. [Crossref] [PubMed]
19. Vergez S, Fakhry N, Cartier C, et al. Guidelines of the French Society of Otorhinolaryngology-Head and Neck Surgery (SFORL), part I: Primary treatment of pleomorphic adenoma. Eur Ann Otorhinolaryngol Head Neck Dis 2021;138:269-74. [Crossref] [PubMed]
20. Porceddu SV, Daniels C, Yom SS, et al. Head and Neck Cancer International Group (HNCIG) Consensus Guidelines for the Delivery of Postoperative Radiation Therapy in Complex Cutaneous Squamous Cell Carcinoma of the Head and Neck (cSCCHN). Int J Radiat Oncol Biol Phys 2020;107:641-51. [Crossref] [PubMed]
21. Giammarile F, Schilling C, Gnanasegaran G, et al. The EANM practical guidelines for sentinel lymph node localisation in oral cavity squamous cell carcinoma. Eur J Nucl Med Mol Imaging 2019;46:623-37. [Crossref] [PubMed]
22. Nenclares P, Ap Dafydd D, Bagwan I, et al. Head and neck mucosal melanoma: The United Kingdom national guidelines. Eur J Cancer 2020;138:11-8. [Crossref] [PubMed]
23. Network. NCC. Head and Neck Cancers. Available online: https://educationnccn.org/2021
24. Lee AW, Ng WT, Pan JJ, et al. International Guideline on Dose Prioritization and Acceptance Criteria in Radiation Therapy Planning for Nasopharyngeal Carcinoma. Int J Radiat Oncol Biol Phys 2019;105:567-80. [Crossref] [PubMed]
25. Geiger JL, Ismaila N, Beadle B, et al. Management of Salivary Gland Malignancy: ASCO Guideline. J Clin Oncol 2021;39:1909-41. [Crossref] [PubMed]
26. Koyfman SA, Ismaila N, Crook D, et al. Management of the Neck in Squamous Cell Carcinoma of the Oral Cavity and Oropharynx: ASCO Clinical Practice Guideline. J Clin Oncol 2019;37:1753-74. [Crossref] [PubMed]
27. Bossi P, Chan AT, Licitra L, et al. Nasopharyngeal carcinoma: ESMO-EURACAN Clinical Practice Guidelines for diagnosis, treatment and follow-up(dagger). Ann Oncol 2021;32:452-65. [Crossref] [PubMed]
28. Ben-Ami T, Kontny U, Surun A, et al. Nasopharyngeal carcinoma in children and adolescents: The EXPeRT/PARTNER diagnostic and therapeutic recommendations. Pediatr Blood Cancer 2021;68:e29018. [Crossref] [PubMed]
29. Cervenka B, Pipkorn P, Fagan J, et al. Oral cavity cancer management guidelines for low-resource regions. Head Neck 2019;41:799-812. [Crossref] [PubMed]
30. Surun A, Schneider DT, Ferrari A, et al. Salivary gland carcinoma in children and adolescents: The EXPeRT/PARTNER diagnosis and treatment recommendations. Pediatr Blood Cancer 2021;68:e29058. [Crossref] [PubMed]
31. Mesia R, Iglesias L, Lambea J, et al. SEOM clinical guidelines for the treatment of head and neck cancer (2020). Clin Transl Oncol 2021;23:913-21. [Crossref] [PubMed]
32. Oncology CSfR. Guidelines for Radiotherapy of Nasopharyngeal Carcinoma in China (2020). Chin J Cancer Prev Treat 2021;28:167-77.
33. Oncology GoCSoC, (CSCO). Guidelines of Chinese society of clinical oncology (CSCO) head and neck cancer 2021 Available online: www.csco.org.cn. 2021.
34. Oncology GoCSoC, (CSCO). Guidelines of Chinese society of clinical oncology (CSCO) nasopharyngeal carcinoma 2020. Available online: www.csco.org.cn. 2020.
35. Babu G, Prabhash K, Chaturvedi P, et al. Indian clinical practice consensus guidelines for the management of hypopharyngeal cancer. Indian J Cancer 2020;57:S16-8. [Crossref] [PubMed]
36. Chaturvedi P, Prabhash K, Babu G, et al. Indian clinical practice consensus guidelines for the management of oral cavity cancer. Indian J Cancer 2020;57:S6-S8. [Crossref] [PubMed]
37. Gairola M, Prabhash K, Babu G, et al. Indian clinical practice consensus guidelines for the management of nasopharyngeal cancer. Indian J Cancer 2020;57:S9-S11. [Crossref] [PubMed]
38. Prabhash K, Babu G, Chaturvedi P, et al. Indian clinical practice consensus guidelines for the management of very advanced disease of squamous cell carcinoma of head and neck. Indian J Cancer 2020;57:S22-5. [Crossref] [PubMed]
39. Prabhash K, Babu G, Chaturvedi P, et al. Indian clinical practice consensus guidelines for the management of oropharyngeal cancer. Indian J Cancer 2020;57:S12-5. [Crossref] [PubMed]
40. Prabhash K, Babu G, Chaturvedi P, et al. Indian clinical practice consensus guidelines for the management of squamous cell carcinoma of head and neck. Indian J Cancer 2020;57:S1-S5. [Crossref] [PubMed]
41. Singhal M, Prabhash K, Babu G, et al. Indian clinical practice consensus guidelines for the management of laryngeal cancer. Indian J Cancer 2020;57:S19-S21. [Crossref] [PubMed]
42. Zhou B, Zhu W, Ren C. First steps to regulate advertising of areca nut in China. Lancet Oncol 2019;20:615-6. [Crossref] [PubMed]