Clinical profile of lung cancer in North India: A 10-year analysis of 1862 patients from a tertiary care center

Abstract

Introduction: Over the past few years, the demographic profile of lung cancer has changed. However, most reports are limited by small numbers, short follow-up period, and show an inconsistent pattern. A comprehensive evaluation of changing trends over a long period has not been done.

Materials and methods: Consecutive lung cancer patients were studied over a 10-year period from January 2008 to March 2018 at the All India Institute of Medical Sciences, New Delhi, and relevant clinical information, and survival outcomes were analyzed.

Results: A total of 1862 patients were evaluated, with mean (SD) age of 59 (11.1) years, and comprising 82.9% males. Majority were smokers (76.2%) with median smoking index of 500 (interquartile range [IQR]: 300-800). Adenocarcinoma (ADC) was the most common type (34%), followed by squamous cell carcinoma (SCC - 28.6%) and small cell lung cancer (SCLC) (16.1%). Over the 10-year period, ADC increased from 9.5% to 35.9%, SCC from 25.4% to 30.6%, and non-small cell lung cancer -not otherwise specified (NSCLC-NOS) decreased from 49.2% to 21.4%. The proportion of females with lung cancer increased although smoking rates remained similar. Majority of NSCLC (95%) continued to be diagnosed at an advanced stage (3 or 4). Epidermal growth factor receptor (EGFR) mutations and anaplastic lymphoma kinase (ALK) rearrangements were present in 25.3% and 11.5% ADC patients, respectively. The median overall survival was 8.8 months (IQR 3.7-19) for all patients and 12.57 (IQR 6.2-28.7) months among the 1013 patients who were initiated on specific treatment (chemotherapy, targeted therapy, radiotherapy, or surgery). Never-smokers were younger, more likely to be female and educated, had a higher prevalence of ADC and EGFR/ALK mutations, and had better survival.

Conclusion: Among this large cohort, our center seems to follow the global trend with increasing incidence of ADC. EGFR mutation positivity was similar to existing reports, while higher ALK positivity was detected. A characteristic phenotype of never-smokers with lung cancer was elucidated which demonstrated better survival.

Keywords: India; lung cancer; smoking; trends.

Figure 1

Year-wise mean age of patients over time period of study. The mean (standard deviation) age of patients over first 5-year block (2008–2012) compared to the next 5-year block (2013 to March 2018) was similar, (57.7 [10.3] years vs. 58.3 [11.3] years), respectively, (P = 0.42)

Figure 2

Depicts the year-wise distribution (%) of adenocarcinoma, squamous cell carcinoma and non-small cell lung cancer (not otherwise specified) over the study period from 2008 to 2018

Figure 3

Year-wise proportion of female among total population and smoking prevalence among females over the time period of the study. The difference of proportion of females over first 5 years (2008–2012) compared to the next 5 years (2013–March 2018) was statistically significant (11.4% vs. 18.4%, P = 0.002); however, the smoking % in females over the two 5-year blocks was not significantly different (32.5% vs. 32.0%, P = 0.95)