Radiotherapy to intervention sites in mesothelioma: no more?

Our plain-English summary of Radiotherapy to intervention sites in mesothelioma: no more?, by G.L. Ceresoli, V. Vavassori (The Lancet. Oncology, 2016).

The study

• Authors: G.L. Ceresoli, V. Vavassori
• Journal: The Lancet. Oncology
• Published: 2016;17(8):1025-1027
• Type of article: Comment
• Cited by: 3 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

In plain English

This is a short commentary, not an original study. The authors, from Bergamo, Italy, discussed the SMART trial, which Amelia Clive and colleagues published separately in the same journal. SMART tested whether radiotherapy to the chest-wall site of a biopsy or other procedure (21 Gy in three fractions) prevents malignant pleural mesothelioma from growing along the procedure tract. As the commentators described it, the trial found no significant difference in procedure-tract metastases between immediate radiotherapy (9 of 102 patients, 9%) and deferred radiotherapy (16 of 101, 16%; odds ratio 0.51, 95% CI 0.19 to 1.32; p=0.14). It also found no difference in quality of life, chest pain or painkiller needs. Among patients not receiving chemotherapy, immediate radiotherapy was linked to a significant reduction in risk (odds ratio 0.16, 95% CI 0.02 to 0.93). The commentators noted that this came from a subgroup analysis that should be confirmed. They concluded that routine prophylactic radiotherapy is not justified in all patients with malignant pleural mesothelioma, although a benefit is suggested in those not receiving chemotherapy.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Commentary (editorial comment) on a separately published phase 3 randomised trial (SMART); not original research
• Who was studied: As described in the comment: patients with malignant pleural mesothelioma in the SMART trial. 457 were screened, 254 were not randomised, and 102 were assigned to immediate radiotherapy and 101 to deferred radiotherapy.
• Exposure: No asbestos exposure was studied. The comment concerns prophylactic radiotherapy to procedure sites, 21 Gy in three fractions over 3 working days, started within 42 days of the procedure. Asbestos is mentioned only as the cause of rising mesothelioma incidence.
• Main results:
  • SMART trial (as reported in the comment): procedure-tract metastases occurred in 9 of 102 (9%) patients given immediate radiotherapy versus 16 of 101 (16%) given deferred radiotherapy. Odds ratio 0.51 (95% CI 0.19 to 1.32), p=0.14; not a significant difference.
  • SMART trial (as reported in the comment): no difference between the groups in quality of life, chest pain, or need for painkilling drugs
  • SMART trial subgroup (as reported in the comment): among patients not receiving chemotherapy, immediate radiotherapy was associated with a significant reduction in procedure-tract metastasis risk (odds ratio 0.16, 95% CI 0.02 to 0.93; p=0.021)
• The authors' conclusion: The commentators concluded that routine prophylactic radiotherapy to thoracic intervention sites is not justified in all patients with malignant pleural mesothelioma, although a benefit is suggested in patients not receiving chemotherapy.
• Limitations the authors state:
  • The chemotherapy finding came from a subgroup analysis and should be confirmed by further studies. Patients were not stratified by whether they received chemotherapy.
  • The trial's eligibility criteria were strict, as shown by the high screen failure rate.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Lung cancer, Mesothelioma.

Medical terms in this study, explained in our Lexicon: Mesothelioma.

Related studies

• Should all patients who have mesothelioma diagnosed by video-assisted thoracoscopic surgery have their intervention sites irradiated? — M. Nagendran, A. Pallis, et al. (2011)
• Intratumoral macrophage phenotype and CD8+ T lymphocytes as potential tools to predict local tumor outgrowth at the intervention site in malignant pleural mesothelioma — R. Cornelissen, L.A. Lievense, et al. (2015)
• Prophylactic irradiation of intervention sites in malignant pleural mesothelioma — M.A. Froment, E. Fréchette, et al. (2011)
• Prevention of malignant seeding at drain sites by hypofractionated radiotherapy in patients with pleural mesothelioma — P. Kara, I. Ugur, et al. (2010)
• Salvage radiotherapy for oligo-progressive malignant pleural mesothelioma — P. Ghirardelli, D. Franceschini, et al. (2021)
• Adjuvant radiotherapy for malignant pleural mesothelioma: challenges and pitfalls — G.L. Ceresoli, U. Ricardi, et al. (2012)

Browse more research in The Lancet. Oncology, or return to medical research.