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Year : 2013  |  Volume : 50  |  Issue : 4  |  Page : 291-

Lung cancer epidemiology and clinical profile in North India: Similarities and differences with other geographical regions of India

N Singh, D Behera 
 Department of Pulmonary Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh, India

Correspondence Address:
N Singh
Department of Pulmonary Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh
India




How to cite this article:
Singh N, Behera D. Lung cancer epidemiology and clinical profile in North India: Similarities and differences with other geographical regions of India.Indian J Cancer 2013;50:291-291


How to cite this URL:
Singh N, Behera D. Lung cancer epidemiology and clinical profile in North India: Similarities and differences with other geographical regions of India. Indian J Cancer [serial online] 2013 [cited 2022 Aug 9 ];50:291-291
Available from: https://www.indianjcancer.com/text.asp?2013/50/4/291/123581


Full Text

Sir,

This is in reference to the mini-symposium on lung cancer epidemiology that was published in a recent issue of your journal. The three articles published therein provided a contemporary view of lung cancer epidemiology from tertiary care centers in West, South, and East India. [1],[2],[3] In this context, we would like to share our recent assessment of the clinico-epidemiological profile of lung cancer in North India.

One of our most important observations has been the lack of change in the distribution of different histologic types with time. At our center, squamous cell carcinoma continues to remain the most common histologic type overall as well as amongst smokers (approximately 38%). [4] Frequency of other histologic types has also remained similar to what was witnessed at our center three decades ago. [5] In addition to histology, the other clinico-epidemiological variables namely gender, disease stage, and smoking profile have also not changed substantially with time. [4]

The second important observation has been the presence of significant differences in the key clinico-epidemiological characteristics between current/former smokers and non-smokers. Current/former smokers had higher mean age, higher percentage of males, higher frequency of squamous and small cell histologies as well as lower percentage of advanced non-small cell lung cancer (NSCLC). [4] Furthermore, when we assessed for presence of these differences in relation to quantified smoking status (using the smoking index) [6] amongst NSCLC patients, we observed a strong and inverse association between heavy smoking and presence of advanced stage as well as of extra-thoracic disease (ETD) at diagnosis. [7] On multivariate analysis, heavy smoking had significantly lower odds as compared to never-smokers for presence of advanced NSCLC (odds ratio [OR] = 0.25; 95% confidence interval [CI] = 0.11-0.61) and for ETD (OR = 0.29; 95% CI = 0.16-0.53). Even on subgroup analyses by histology and gender, the inverse and independent association of heavy smoking with advanced disease and ETD was consistently observed amongst NSCLC patients. Interestingly, non-squamous histology had significantly higher odds as compared to squamous histology for presence of ETD (OR = 2.31; 95% CI = 1.50-3.57).

The third important association that we have noted has been the high incidence (approximately 45%) of low body mass index (BMI) among newly diagnosed lung cancer patients. [8] Here again, heavy smoking was found to have an independent association with presence of low BMI (OR = 3.74; 95% CI = 1.59-8.80).

Bidi smoking is the most common type of smoking product in India overall, and the same has been observed by us amongst lung cancer patients presenting to our center. [7],[9] It is possible that some or all of the above mentioned observations are in part linked to the continued predominance of bidi smoking in North India. These data also suggest that India has geographical diversity not just for its population profile, but even for a disease like lung cancer. Longitudinal studies can help to assess whether temporal trends that have been witnessed globally and perhaps in some geographical regions of India are observed in other areas as well.

References

1Noronha V, Dikshit R, Raut N, Joshi A, Pramesh CS, George K, et al. Epidemiology of lung cancer in India: Focus on the differences between non-smokers and smokers: A single-centre experience. Indian J Cancer 2012;49:74-81.
2Krishnamurthy A, Vijayalakshmi R, Gadigi V, Ranganathan R, Sagar TG. The relevance of "Nonsmoking-associated lung cancer" in India: A single-centre experience. Indian J Cancer 2012;49:82-8.
3Dey A, Biswas D, Saha SK, Kundu S, Kundu S, Sengupta A. Comparison study of clinicoradiological profile of primary lung cancer cases: An Eastern India experience. Indian J Cancer 2012;49:89-95.
4Singh N, Aggarwal AN, Gupta D, Behera D, Jindal SK. Unchanging clinico-epidemiological profile of lung cancer in north India over three decades. Cancer Epidemiol 2010;34:101-4.
5Jindal SK, Behera D. Clinical spectrum of primary lung cancer: Review of Chandigarh experience of 10 years. Lung India 1990;8:94-8.
6Jindal SK, Malik SK, Dhand R, Gujral JS, Malik AK, Datta BN. Bronchogenic carcinoma in Northern India. Thorax1982;37:343-7.
7Singh N, Aggarwal AN, Gupta D, Behera D, Jindal SK. Quantified smoking status and non-small cell lung cancer stage at presentation: Analysis of a North Indian cohort and a systematic review of literature. J Thorac Dis 2012;4:474-84.
8Singh N, Aggarwal AN, Gupta D, Behera D. Prevalence of low body mass index among newly diagnosed lung cancer patients in North India and its association with smoking status. Thoracic Cancer 2011;2:27-31.
9Jindal SK, Aggarwal AN, Chaudhry K, Chhabra SK, D′Souza GA, Gupta D, et al. Tobacco smoking in India: Prevalence, quit-rates and respiratory morbidity. Indian J Chest Dis Allied Sci 2006;48:37-42.