Indian scientists identify genetic markers to predict immunotherapy response in oral cancer patients

New Delhi: Opening a new window for oral cancer treatment, Indian biologists have discovered the underlying genetic signatures of the commonest type of oral cancer, which doctors can exploit to identify the patients who may respond better to a new class of cancer therapy.

Relying on the expressions of three specific genes, the scientists including a researcher from Yenepoya University, Mangalore, are now developing a low-cost diagnostic tool that in future can allow segregation of such patients in clinics for immunotherapy.

India bears the highest burden of oral cancer in the world and its commonest form is known as gingivo-buccal oral cancer involving inner cheek and gum but not the tongue. This is the most common cancer among males.

Doctors currently treat most patients in similar ways using combinations of surgery, radiation therapy and chemotherapy. But these treatments do not work equally well for all patients.

One possible reason, the scientists argue, may be that cancers of different patients behave differently due to a variation in the level of gene-expression – the process through which genetic information is translated into an action in the body.

The researchers decided to investigate. After a detailed examination of cancer tissues collected from 72 patients, they found ways to separate the victims of oral cancers into two distinct biological groups by estimating the levels of gene expression in cancer cells of different patients.

Laboratory tests suggest that patients who belong to the largest group may respond better to modern immune-based cancer treatments.

“We will validate the data in a larger sample and will also work on the development of a prototype of a low-cost chipset for diagnosis,” team leader Partha Majumder, emeritus professor at Indian Statistical Institute, Kolkata told DH, noting that clinical trials would be required before doctors can use such a technique.

Majumder and his colleagues from Tata Memorial Hospital in Mumbai; R Ahmed Dental College and Hospital and Chittaranjan National Cancer Institute in Kolkata; National Institute of Biomedical Genomics, Kalyani and Yenepoya University examined the activities of thousands of genes in each tumour sample and compared the cancer cells with nearby healthy tissue of that patient.

By studying which genes are highly active and which are not, they got insights on how a cancer grows and interacts with the body, besides finding a way to distinguish between the two groups.

The team identified three genes - CD226, CD38 and KBTBD8 - that could help distinguish between the two patient groups in 86 of per cent cases, suggesting that a laboratory test based on these genes may help doctors identify whether a patient will benefit from immunotherapy.

India accounts for over 30 per cent of the world's total oral cancer cases and approximately 55 per cent of all diagnosed oral cancer cases in India result in death, heavily driven by late-stage detection.

In a previous research paper, doctors at the Tata Memorial Centre showed that the total cost of lost productivity due to premature oral cancer mortality in India in 2022 was $5.6 billion, representing 0.18 per cent of the combined gross domestic product.

The study was published in the journal Molecular Medicine last week.