Higher rate of cancer among women; oral cancer most common among men: How India’s 4-year cancer registry maps incidence

* Cancer occurrence was among the highest in the northeastern states.

These are some of the key findings of an analysis by researchers from premier institutions of data collected from 43 cancer registries across the country between 2015 and 2019 — a period when 7.08 lakh cancer cases and 2.06 lakh deaths were recorded.

Based on the analysis, the researchers also estimated that a total of 15.6 lakh cancer cases and 8.74 lakh deaths occurred across the country in 2024.

Population-based cancer registries collect data on new cancer cases, deaths and trends in selected geographical areas. India’s registry currently covers 23 states and Union Territories, either partially or fully, and monitors trends in 10% to 18% of the population, with newer registries in regions such as Kashmir, Prayagraj and Thiruvananthapuram.

The analysis was conducted by a group of national investigators from data collected by various hospitals, such as AIIMS-Delhi, Adyar Cancer Institute-Chennai, PD Hinduja-Mumbai, Tata Memorial Centre-Navi Mumbai, and Assam Medical College and Hospital. The data for 2020 was not included in the analysis due to the impact of Covid on health systems and the registry.

The Government has several cancer care programmes in place and on the anvil, including, screening at the lowest levels through health and wellness centres, day care centres to be rolled out across all districts and treatment in tertiary centres under Ayushman Bharat. It has also been working on making newer cancer drugs cheaper by cutting related duties.

The key trends that emerged from the analysis of registry data include:

Women see higher case rate

Dr Prashant Mathur, director, ICMR-National Centre for Disease Informatics and Research, which coordinates the country’s cancer registry, said the gender disparity is linked to the time taken for diagnosis. “The apparent disparity of more cases but fewer deaths can largely be explained by the types of cancers most common in women. Breast and cervical cancers together account for 40% of female cancers and generally have better prognosis, higher survival and established screening programmes that support earlier detection and treatment. In contrast, men experience higher mortality because their leading cancers — oral, lung, liver, stomach and oesophagus — are often diagnosed late and have poorer outcomes,” said Mathur, who led the group of investigators.

“Our recent survival analysis also indicates that women with oral cancers tend to have slightly better survival rates than men,” he said.

Oral cancer on the rise

This was noted among men in 14 of the 43 registries and among women in four registries. Besides, oral cancer overtaking lung cancer as the most common type among men is significant because the use of tobacco has gone down over the years — the proportion of adults using tobacco in India reduced from 34.6% to 28.6% between two rounds of the Global Adult Tobacco Survey 1 (2009-10 and 2016-17).

“Evidence from cancer studies suggests that it often takes at least 20 or more years for cancer to develop after the first exposure to a carcinogen like tobacco. The long latency period may explain why oral cancer rates continue to rise despite recent reductions in tobacco use. High alcohol consumption, another established risk factor for oral cancer, also contributes to this burden,” says Mathur.

According to Dr Abhishek Shankar, oncologist from AIIMS-Delhi, alcohol consumption is a known risk factor for at least seven types of cancers, including oral cancers, apart from liver cancer. “It also increases the risk of gastric and colorectal cancers that are among the common cancers in men. While both alcohol and tobacco consumption are individually known to increase risk of cancers, together they are known to compound it,” said Shankar, who is not associated with the study.

More screening for women

While the proportion of cancer deaths among women is lower, the researchers have underlined the scope for awareness, screening and other measures such as vaccination. For instance, breast cancer, which makes up 30% of cancers in women, can be detected early through screening thereby improving chances of survival.

Mathur said cervical cancer incidence was below 4 per 100,000 in only two registries and emphasised the need to strengthen screening, HPV vaccination and awareness.

Northeast alert

The highest cancer incidence across the 43 registries was reported from Aizawl in males (198.4 per 100,000) and females (172.5 per 100,000). Lifestyle, environment and infectious risk factors led to this high burden in the northeastern states, Mathur said.

“The use of tobacco among females and males in all the Northeastern states is significantly higher than the national average. Besides tobacco, betel nut chewing and certain dietary habits, such as consumption of sa-um (fermented pork fat), smoked dried salted meat and fish, very spicy food, hot beverages, and the use of soda as a food additive, also contribute to cancer risk,” he said.

“Moreover, the prevalence of infections such as Helicobacter Pylori, hepatitis, salmonella typhi, Human Papilloma Virus (HPV), etc., which may act as carcinogens in several cancers, is also high in the region,” Mathur said.

According to Shankar, the use of preservatives and the smoking of meat increases the exposure to nitrogen compounds. “These are known to increase cancer risk. There is a high prevalence of smoking and drinking in these states that increase the risk of several cancers. The use of fire to heat up houses also leads to increased indoor pollution,” he said.

Geographical spread

The highest incidence of breast cancer was in Hyderabad (54 per 100,000 population) while that of cervical cancer was in Aizawl (27.1). The highest occurrence of lung cancer in men was in Srinagar (39.5) and among women in Aizawl (33.7). Lung cancer emerged as the most frequently diagnosed cancer in the southern areas and metropolitan cities, including Visakhapatnam, Bengaluru, Kollam, Thiruvananthapuram, the Malabar region, Chennai and Delhi.

The highest incidence of oral cancer in men was in Ahmedabad (33.6) and among women in East Khasi hills (13.6). Mouth cancer was found to be the most common in some western (Ahmedabad Urban, Bhopal, Nagpur and Wardha), central (Barshi Rural, Mumbai, Aurangabad, Osmanabad, Beed, Pune, Sindhudurg and Ratnagiri) and northern (Prayagraj and Varanasi) regions.

Srinagar (12.7) recorded the highest incidence of prostate cancer.

According to the experts, the geographical spread underscores the need to have a national as well as state-level plans in place, with related medical infrastructure and human resources to be scaled up accordingly.