Treating Mesothelioma: Chemotherapy Success Rate

Treatment // February 1, 2018

Depending on the stage and type of mesothelioma, chemotherapy has been a standard treatment option for many years. Even with continued research into emerging treatments like immunotherapy, mesothelioma doctors often still rely on some kind of treatment combination that also involves chemotherapy.

But even though chemotherapy remains a standard of care for the rare, aggressive cancer, this treatment doesn’t necessarily always have the best results for long-term survival. For some patients, it can also be very difficult to tolerate the toxicity and side effects of chemotherapy.

Can Chemotherapy Cure Mesothelioma?

Unfortunately, even with continued research, doctors have yet to find a cure for mesothelioma. There have been some advancements with promising new diagnostic techniques and potential new treatments that can extend life expectancy, but there is still a long way to go. Researchers have seen mesothelioma survival rates improve a bit in more recent years, which many correlate with these newer treatment approaches.

Though chemotherapy cannot cure mesothelioma, it may still be a good option for many patients to extend survival, especially for those who are not candidates for cytoreductive surgery. Chemotherapy works by killing cancer cells and preventing the cells from multiplying and spreading. Depending on a patient’s case, chemotherapy may be used as a first, second or even third line of treatment, which indicates what order in a multimodal treatment plan chemotherapy would be applied. A big aspect of ongoing research is testing different orders and combinations of these standard treatments, like chemotherapy and surgery, especially with emerging treatments showing promise.

While there are a number of chemotherapy drugs available and used to treat mesothelioma cancer, Alimta or pemetrexed is the first and only chemotherapy drug to be FDA approved to treat the cancer. Alimta is most often used in combination with another chemotherapy drug cisplatin, which is a platinum-based drug, after the combination showed a median survival of 12 months in clinical trials. Though this is the considered the standard of care, other clinical trials have found higher success rates in longer survival with other chemotherapy combinations, including among those with mesothelioma in the later stages.

Learn More About Chemotherapy and Other Mesothelioma Treatment Options

Chemotherapy Success Rate for Pleural Mesothelioma

Chemotherapy on its own hasn’t been found to be the most successful treatment for pleural mesothelioma. A treatment study found that of pleural mesothelioma patients treated with chemotherapy alone, only about 19% survived two years after diagnosis. After five years, a mere 4% of these patients were still alive. The study found patients who underwent cytoreductive surgery, typically part of a multimodal approach, achieved much better survival rates than chemotherapy by itself, with about 40% surviving two years and 10% – 12% surviving five years.

It’s important to keep in mind the success and efficacy of chemotherapy can vary greatly between patients due to a number of factors, like cell type or a patient’s overall health. Sarcomatoid mesothelioma, for instance, doesn’t respond well to treatment, but epithelioid mesothelioma may have a more positive response to chemotherapy.Though that particular study didn’t see very promising results from chemotherapy overall, some patients have seen extended survival. For instance, the drug doxorubicin in combination with cisplatin was found to extend survival to nearly 20 months for patients with stage 3 and stage 4 mesothelioma.

Many clinical trials have studied the side effects and overall survival of a variety of chemotherapy combinations. A more recent trial tested the efficacy of alimta and cisplatin with 225 pleural mesothelioma patients between 2008 and 2014. On average, the patients saw an overall survival of about 16 months. This clinical trial compared this standard chemotherapy combination against the efficacy of the same combination with the addition of bevacizumab, also known as avastin. Bevacizumab is a type of immunotherapy called monoclonal antibody, which works by targeting particular proteins or processes that would help tumor growth. The triplet therapy resulted in an improved overall survival of nearly 19 months, though patients faced much harsher side effects.

Just last summer, the National Comprehensive Cancer Network updated the first-line treatment for pleural mesothelioma to include the new triplet therapy as a viable option. Hopefully with further testing, this chemotherapy and immunotherapy combination can lead to better long-term survival rates.

Chemotherapy Success Rate for Peritoneal Mesothelioma

In recent studies, researchers have found improving peritoneal mesothelioma survival rates largely in part to a particular treatment combination. Cytoreductive surgery followed by a heated chemotherapy wash, Hyperthermic Intraperitoneal Chemotherapy or HIPEC, in the abdominal cavity has shown a 5-year survival rate as high as 67%.

This specific kind of chemotherapy is very targeted, as it’s only exposed directly to the abdomen, unlike most chemotherapy drugs applied intravenously and impacting the entire body. With this kind of application, doctors are able to use a more highly concentrated dose of chemotherapy. The solution is also heated to around 100 degrees, with the understanding that the heat will help the cancer cells better absorb the solution and ultimately be destroyed. After surgery, which is meant to remove all visible tumors, the oncologists can apply the chemotherapy solution to the area for around two hours to hopefully kill any remaining cancer cells left behind from surgery.

Across various clinical trials of this treatment method, researchers have found on average 40 –  50% of patients are able to survive at least five years. One clinical trial even found an average survival of 92 months, which far exceeds the average mesothelioma prognosis. With such successful prolonged survival, this multimodal treatment approach has become the most promising for peritoneal mesothelioma, though not all patients are eligible for surgery. For those patients, similar combinations of chemotherapy drugs used in treating pleural mesothelioma may be an option, with studies showing an average survival of 12 – 27 months.

Chemotherapy has been a standard treatment for all types of cancers for many years, and that likely won’t change an time soon. Though the success of prolonged survival can fluctuate a lot between the types of mesothelioma and the drug combinations, the treatment has been able to help many patients achieve longer survival.