Carboplatin with chemotherapy increases survival in triple-negative breast cancer: TMC study

Results showed a 77% survival rate in patients below 50 years who used carboplatin, an increase from the 66% without it

MUMBAI: A low-cost, platinum-based chemotherapy drug, carboplatin, can now be utilised to increase chances of survival among women with aggressive breast cancer, as per a 10-year-long study and Phase-3 clinical trial conducted by Tata Memorial Centre (TMC).

healthcare, people and medicine concept - close up of women in blank shirts with pink breast cancer awareness ribbon over white background (Getty Images/iStockphoto)

The total cost of carboplatin for the entire eight-week treatment is estimated to be between ₹5,000 and ₹6,000, ranging from ₹625 to ₹750 per dose every week. The total cost drugs for the eight-week treatment and chemotherapy comes up to ₹25,000.

The study, funded by the Department of Atomic Energy, included 720 women with locally advanced stage 3 triple-negative breast cancer (TNBC) and was conducted from 2010 to 2020.

TNBC is an aggressive form of breast cancer which occurs when the tumour lacks receptors for the hormones estrogen and progesterone, and the HER2 protein, receptors that help control how breast cells grow. The tumour then spreads fast and is only treatable through chemotherapy and surgery.

Under standard treatment for TNBC, patients are administered chemotherapy before surgery to shrink the tumour. In this study, half the patients received standard chemotherapy (paclitaxel for eight weeks, followed by doxorubicin plus cyclophosphamide every 21 days for four cycles). Meanwhile, the other half were given an additional drug, carboplatin, through intravenous infusion once a week for eight weeks, along with their other chemotherapy drugs.

Patients were monitored for relapses for close to six years after the first conclusion of their treatment. TNBC relapse typically occurs within the first five years after treatment, with 75% of recurrences occurring during this time.

Results showed a 77% survival rate in patients below 50 years who used carboplatin, an increase from the 66% without it. For those above 50 years, a 74.4% survival rate was noticed, a 7.6% increase from the 66.8% recorded in regular chemotherapy.

“The treatment was well tolerated by most patients. Only mild platelet reduction was observed, which was not clinically significant,” Dr Sudeep Gupta, director of the TMC, said, who is also the lead author of the study. “This provides the first definitive proof that including a platinum drug like carboplatin improves survival and that this simple, affordable addition can save lives.”

The researchers noted that 45% of the women in the cohort who were diagnosed with TNBC were below 50 years old. In India, around 1.8 lakh new breast cancer cases are recorded annually, of which one-third, nearly 60,000, are TNBC. Around 70% of these cases occur in women below 50 years of age, they said.

“The addition of carboplatin to standard chemotherapy can be implemented in regular clinical settings as it is cost-effective and requires minimal logistical changes. Additionally, the drugs are also covered under state insurance schemes, which makes them more accessible to all patients. We have already started utilising it in the TNBC cases we observe at TMC,” said Dr Rajendra A. Badwe, honorary professor Emeritus at TMC and principal investigator of the trial.

Researchers also found that the expected improvement in survival was not observed in a subset of patients. A companion study is underway to examine this aspect. “We are currently analysing RNA sequencing of tumour samples to understand biochemical resistance in the patients. Identifying this mechanism will help us refine future treatment strategies,” said Dr Gupta.

According to the team, the results are relevant for global clinical practice. “Once efficacy is validated in large-scale studies such as this, carboplatin can be integrated into treatment protocols across centres worldwide. The drug was available previously, but no one understood whether it would be effective. But now that it is established, it will be used worldwide,” Dr Badwe said.