New Radiation Therapy for Recurrent Pleural Mesothelioma

New Radiation Therapy for Recurrent Pleural Mesothelioma

Malignant pleural mesothelioma is often diagnosed in the later stages of disease when aggressive treatment may no longer be viable. Although treatment options may be limited, survival is possible. Even for patients diagnosed at an earlier stage with more treatment options, recurrent disease may occur.

There is a new treatment option for patients with recurrent pleural mesothelioma. Researchers found success using radiation to extend survival for patients without harsh side effects.

Researchers Achieve Controlled Tumor Growth Through Targeted Radiation

Treating mesothelioma patients who experience tumor growth following remission is difficult. Often, first-line treatments have taken a toll on the patient’s body. To achieve tumor control with recurrent disease, mesothelioma doctors need an effective treatment without harsh side effects.

A recent retrospective study from researchers in Switzerland found a promising treatment for recurrent pleural mesothelioma. The study followed 21 pleural mesothelioma patients from 2010 to 2018. All patients were previously treated for the cancer.

When the patients experienced recurrence, they received stereotactic body radiotherapy. This targeted radiation treatment avoids healthy surrounding tissue.

Stereotactic Body Radiotherapy: Physicians use three-dimensional images of tumors to accurately direct radiation at tumors in specific locations within the body.

The Swiss researchers analyzed patient outcomes following the treatment. After 12 months, 73.5% of treated tumors had not grown. This result indicates the treatment was able to control cancer growth.

Patient Characteristics Within the Study

Although all patients included in the study had recurrent pleural mesothelioma, other characteristics varied between the individuals. Patient characteristics (such as age) may impact the efficacy of the treatment.

In this specific case, more than 80% of patients had epithelioid mesothelioma. This cell type typically responds more favorably to treatment than the other mesothelioma cell types.

Additionally, most study participants had stage 1, 2 or 3 disease. Patients with late-stage disease often have shorter life expectancies. Researchers note if participants had end-stage mesothelioma or aggressive cell types, results may have differed.

  • Median Age at First Diagnosis: 65 years old
  • Age Range: 33 – 75 years old
  • Male: 81%
  • Female: 19%
  • Stage 1: 14.3%
  • Stage 2: 19%
  • Stage 3: 57.1%
  • Stage 4: 9.5%
Cell Type
  • Epithelioid: 81%
  • Sarcomatoid: 9.5%
  • Biphasic: 9.5%

Promising Option for Patients With Recurrent Disease

Results from the study show promise for those impacted by asbestos disease. The median overall survival among study participants was 29 months. The median survival for patients treated with typical multimodal therapy approaches is 23 months.

Median progression-free survival was six months among study participants.

Progression-Free Survival: The period of time during and after treatment that patients do not experience any growth of tumors.

The researchers stated the ability to prolong survival in those with cancer recurrence is encouraging. This is not the first study to report such results.

In a case study from 2012, researchers reported a patient achieved 40 months disease-free. This pleural mesothelioma patient received a pleurectomy/decortication followed by radiation and chemotherapy. Upon recurrence of the mesothelioma, the 62-year-old patient underwent radiosurgery. He had no severe side effects but experienced some nerve pain at the treatment site.

The individual in the case study has similar patient characteristics to the 21 participants in the Swiss study.

Limitations of Study Require Further Research

Although the results are promising, further research is needed. The researchers noted study limitations including the variety of patients’ first-line treatments. The array of treatment types may impact the resulting data.

One of the greatest challenges with the study involves balancing risk with results. The desired efficacy of the treatments cannot come with severe side effects.

Overall, toxicity levels for study participants were low. Among the 21 individuals, there was one instance of grade three toxicity. This patient experienced upper gastrointestinal bleeding and died during the follow-up period. Researchers believe the death was caused by a combination of the targeted radiation therapy and progressing disease.

To mitigate toxicity issues, the researchers suggest further analysis of the optimal radiation volume. Although targeted radiation therapies reduce the risk of damage to healthy tissue, there is still uncertainty around how strong the radiation needs to be to eradicate the tumors. Proper radiation levels will:

  • Ensure all cancerous tumors receive a sufficient dose of treatment
  • Spare abdominal organs, which may be near mesothelioma tumors

Targeted radiation for recurrent mesothelioma is one example of a promising emerging treatment for mesothelioma patients. Patients experiencing recurrence should discuss all treatment options with their medical team. Viable treatment options will vary on a case by case basis.