Recognition of and treatment recommendations for oligometastatic disease in multidisciplinary tumor boards

Our plain-English summary of Recognition of and treatment recommendations for oligometastatic disease in multidisciplinary tumor boards, by S.M. Christ, P. Heesen, U.J. Muehlematter, et al (Clinical and Translational Radiation Oncology, 2023).

The study

• Authors: S.M. Christ, P. Heesen, U.J. Muehlematter, K. Pohl, G. William Thiel, J. Willmann, M. Ahmadsei, T.E. Kroese, M. Mayinger, P. Balermpas, A. Wicki, N. Andratschke, M. Huellner, M. Guckenberger
• Journal: Clinical and Translational Radiation Oncology
• Published: 2023;38:123-129
• Cited by: 8 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Background And Introduction: Growing evidence supports a combined modality treatment strategy for patients with oligometastatic disease. However, lack of phase III trial data and uncertainties around patient selection highlight the importance of multidisciplinary tumor boards (MDT) in therapeutic decision-making. This study aimed to analyze the recognition of and treatment recommendations for oligometastatic patients by MDTs at a large comprehensive cancer center in order to better understand current treatment patterns of oligometastasis.

Materials And Methods: For this retrospective single-center cross-sectional study, oligometastatic patients were identified by screening oncological PET and concurrent brain MRI scans conducted at our center in 2020. MDT discussions and recommendations within four weeks of the imaging diagnosis of oligometastasis were analyzed. Logistic regression analysis was used to identify predictors for the addition of local therapy to standard-of-care.

Results: A total of 787 oligometastatic cases were identified. Lung cancer and mesothelioma, skin cancer, and prostate cancer were the most common histologies with 231 (29 %), 160 (20 %), and 84 (11 %) cases, respectively. Almost half of the cases (46 %) had one distant metastasis on imaging only. More than half (56 %) of all oligometastatic cases were discussed at an MDT. In 47 % of cases, for which a therapeutic recommendation was reached in an MDT, local therapy was part of the therapeutic strategy. On logistic regression analysis, oligometastatic skin cancer was significantly associated with a recommendation for local therapy (p < 0.05), whereas the number of oligometastases was not (p = 0.202).

Conclusion: More than half of oligometastatic cases were discussed in MDTs, of which more than every second received a recommendation including the addition of local therapy. This frequency of MDT use underscores the importance of multidisciplinary decision-making, yet efforts should be increased to standardize reporting and use standard nomenclature on oligometastasis in MDTs to better frame multidisciplinary discussion.

© 2022 The Author(s).

In plain English

This retrospective single-center cross-sectional study, at the Comprehensive Cancer Center Zurich, examined how multidisciplinary tumor boards handled oligometastatic cancer: one to five distant metastases, inside or outside the skull, on PET and available brain imaging. It did not study asbestos exposure. Screening 2020 scans identified 787 oligometastatic cases. The largest group, 231 (29%), was lung cancer and mesothelioma combined, and mesothelioma was not reported separately. Of 615 cases followed at the center, 347 (56%) were discussed at a tumor board within four weeks. Boards made a treatment recommendation in 278 of these, including local therapy in 130 of 278 (47%). The term "oligometastasis", counting variants like oligoprogression, was documented or mentioned in only 10 of 347 discussions. Multivariable analysis gave skin cancer cases, versus all other cancers, higher odds of a local therapy recommendation (odds ratio 1.58, 95% confidence interval 1.02 to 2.47). More than one metastasis was linked to lower odds in the single-factor analysis, but not the multivariable one. The authors concluded that multidisciplinary decision-making matters and that reporting and terminology should be standardized. They noted biases from the single-institution, retrospective design.

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: retrospective single-center cross-sectional study of tumor board discussions and recommendations
• Who was studied: 787 cases of oligometastatic disease, counting repeat scans per patient, at the Comprehensive Cancer Center Zurich, Switzerland, January to December 2020. Oligometastatic disease was defined as one to five distant metastases (extracranial plus intracranial) on oncological PET scans and on brain imaging where available. Of these cases, 615 were followed at that center. Lung cancer and mesothelioma were counted together (231 cases, 29%), and this group also included small-cell and non-small cell lung cancer.
• Main results:
  • Of 615 oligometastatic cases followed at the center, 347 (56%) were discussed at a tumor board within four weeks of the PET scan.
  • A treatment recommendation was made in 80% (278 of 347) of tumor board discussions of oligometastatic cases. In the other 20% (69 of 347), further diagnostic work-up or watchful waiting was recommended.
  • Local therapy was part of the recommended treatment in 47% (130 of 278) of the cases that received a treatment recommendation.
  • Among the 130 cases recommended local therapy, radiotherapy alone was recommended in 55 (42%), surgery alone in 23 (18%), and a multimodal approach including radiotherapy or surgery in 52 (40%).
  • The term "oligometastasis" was documented or mentioned in only 10 cases (3% of the 347 oligometastatic case discussions). The study recorded mentions of the term in all its variants, such as oligoprogression and oligorecurrence.
  • Skin cancer cases, compared with all other primary histologies, had higher odds of a local therapy recommendation. In univariable analysis the odds ratio was 1.646 (95% CI 1.070 to 2.533; p = 0.023). In multivariable analysis it was 1.58 (95% CI 1.02 to 2.47; p = 0.042).
  • Cases with more than one distant metastasis were less likely to be recommended local therapy in univariable analysis (odds ratio 0.80; 95% CI 0.66 to 0.95; p = 0.014). This was not statistically significant in multivariable analysis (odds ratio 0.878; p = 0.202).
  • Gender, age at primary diagnosis, and synchronous versus metachronous disease were not significantly associated with a local therapy recommendation in univariable analysis.
• The authors' conclusion: The authors concluded that local therapy was recommended for about half of the oligometastatic cases that received a treatment recommendation. They wrote that these findings underscore the importance of multidisciplinary decision-making, and that efforts should be increased to standardize reporting and use standard terminology on oligometastasis in tumor boards.
• Limitations the authors state:
  • The study is open to biases arising from its single-institution, retrospective design.
  • It is unclear how representative the sample is of all oligometastatic cases discussed at the center, because cases were selected from imaging rather than from a systematic review of all tumor board reports.
  • Patients may have been discussed at a tumor board before the study's evaluation period, and the analysis did not capture those discussions.

Topics

Medical terms in this study, explained in our Lexicon: Tumor Board, Lung Cancer, Mesothelioma, Metastasis.

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