When Cancer Returns

India is grappling with a burgeoning cancer epidemic. According to the GLOBOCAN Fact Sheet, this low-income country, with a per capita GDP of USD 2,301 in 2022, is home to 1.35 billion people. Shockingly, nearly 1.3 million of them are diagnosed with cancer annually, and approximately 850,000 succumb to the disease. These figures paint a grim picture, with one in ten Indians projected to develop cancer in their lifetime.

The National Cancer Registry Programme Report 2020, published in the National Library of Medicine, offers a more granular perspective. Analysing data from 28 Population-Based Cancer Registries (PBCRs) between 2012 and 2016, the report estimates 1,461,427 new cancer cases in India for 2022, equating to a crude rate of 100.4 per 100,000 population. A disconcerting trend is the anticipated 12.8 per cent increase in cancer cases by 2025 compared to 2020.

India’s Cancer Burden Compared on a Global Scale

Dr. Ankur Bahl, Senior Director of Medical Oncology & Hematology at Fortis Hospital, Gurugram, notes that India’s cancer burden is significant and rising due to its large population. While the overall incidence rate is lower compared to developed countries, global cancer statistics for 2022 reported nearly 20 million new cases and close to 10 million deaths, with a predicted increase to 35 million annual cases by 2050.

“India’s predicted cancer burden for 2021 was 26.7 million DALYs (disability-adjusted life years), expected to increase to 29.8 million by 2025. The leading cancers in India include lung (10.6 per cent), breast (10.5 per cent), oesophagus (5.8 per cent), mouth (5.7 per cent), stomach (5.2 per cent), liver (4.6 per cent), and cervix uteri (4.3 per cent),”  Dr Bahl remarked.

The Most Common Cancers in India

Lung cancer is the primary malignancy among men, while breast cancer disproportionately affects women, according to the National Cancer Registry Programme Report. Childhood cancers, particularly lymphoid leukaemia, pose a significant threat to young lives, the report highlights.

Factors Driving Increased Diagnoses

Dr Meenu Walia, Vice Chairman of Medical Oncology at Max Super Speciality Hospital, Patparganj, identifies several interrelated factors. “The rise in cancer diagnoses across India is driven by several factors. Urbanisation has led to a more sedentary lifestyle and increased consumption of tobacco, alcohol, and processed foods, all contributing to higher cancer risk. Additionally, the aging population and longer life expectancy naturally increase cancer incidence. Environmental factors, such as exposure to pollution and carcinogenic substances, also play a significant role. Genetic predispositions and improvements in medical diagnostics and healthcare infrastructure have led to earlier and more accurate cancer detection, further contributing to the increased number of reported cases, " she explained.

Tests Matters

Dr Pooja Babbar, Consultant in Medical Oncology at CK Birla Hospital, Gurugram, states, “Cancer screening cannot be universally applied but should focus on individuals at risk. For women, screening guidelines are in place for breast and cervical cancers. Women with suspicious breast symptoms such as lumps or pain should get a breast ultrasound before age 40. After 40, annual mammography is recommended, which can reduce breast cancer mortality by 20 per cent. For cervical cancer, which is linked to the HPV virus, screening begins with Pap smear testing at age 21 or three years after sexual activity and continues every three years. HPV testing, which is more sensitive after age 30, can be combined with Pap testing every five years.”

“For males, prostate cancer screening starts at age 50 with serum PSA testing and pelvic ultrasound. Enhanced screening is also advised for individuals with a family history of breast, ovarian, or colon cancer. Those with a family history of breast cancer should undergo germline testing for genes like BRCA and MMR, which are associated with hereditary cancer syndromes,”  Dr Babbar added.

Understanding Recurrent Cancers

Even after undergoing treatment, cancer can return, known as recurrent cancer. It occurs when cancer cells that were not eliminated during initial treatment resurface and multiply.

The National Cancer Institute explains that these cells may be too small to detect initially but can develop into tumours later. Recurrent cancer can be local (returning in the same area), regional (spreading to nearby lymph nodes or tissues), or distant (reappearing in distant organs). Certain cancers, such as glioblastoma, ovarian cancer, and soft tissue sarcomas, have high recurrence rates, while cancers detected and treated early, like estrogen receptor-positive breast cancer and Hodgkin lymphoma, tend to have lower recurrence rates.

Understanding the Biological Mechanisms of Cancer Recurrence

Dr. Ritika Harjani Hinduja, Consultant in Radiation Oncology at P.D. Hinduja Hospital and Medical Research Centre, Mahim, outlines advances in understanding cancer recurrence. “With advances in medical sciences, we are able to cure many cancers when detected early. Researchers are now able to understand the biological mechanisms and genomic changes or mutations that are acquired or used by cancer cells to cause growth. For instance, lung cancer cells that are EGFR receptor positive and started on first-line EGFR receptor-targeted therapy can develop the T790M mutation, which makes first-line EGFR therapy like erlotinib ineffective and the cancer resistant,” she explains.

Another expert,  Dr Babbar, adds, “Cancer recurrence is often attributed to a combination of factors including the resilience of cancer stem cells, the ability of cancer cells to enter a dormant state, the tumour's capacity to induce blood vessel growth, and the body's immune response. Tumor dormancy, in particular, can lead to a prolonged asymptomatic phase, mimicking a chronic disease, as seen in cancers like breast and prostate.”

Tackling Cancer Recurrence

Harjani emphasises ongoing efforts to combat cancer, stating, “In our battle against recurring cancer, specialists and researchers are developing new and more effective treatments. Immunotherapy, which activates the body’s immune system, and targeted therapies like Osimertinib for T790M mutations are now integral to treatment.”

She adds, “Advanced radiation techniques such as SBRT and SRS deliver high doses of radiation directly to tumors while sparing surrounding tissues. This approach is transforming the treatment of metastatic cancer, allowing for curative intent even with limited spread.”

Tailoring Treatment Approaches 

Dr Prasad Eswaran, Senior Consultant in Medical Oncology at Apollo Proton Cancer Center, Chennai, acknowledges the challenges of cancer recurrence but highlights recent advancements. “Cancer recurrence remains difficult for patients, families, and doctors. However, India has made significant strides in cancer care over the past decade and is becoming a leader in global medical tourism. Advanced molecular tests, previously available only in the West, are now accessible in major Indian cities, including PET-CT scans, 3 Tesla MRI, and serum tumour markers, which have improved follow-up care,” Eswaran said.

“With government initiatives facilitating access to newer generic drugs, patients can now better manage recurrent cancers and maintain a good quality of life. Risk factors for cancer vary by type and include hereditary factors such as BRCA mutations, obesity, and factors related to pregnancy and breastfeeding. Hereditary risks can be addressed through genetic counselling and risk reduction strategies, while lifestyle factors like obesity and high estrogen levels can be managed through exercise and healthy habits,” he added.

Arya Rakshita

BW Reporters Trainee Correspondent