Complete Response of Metastatic Melanoma to Local Radiation and Immunotherapy: 6.5 Year Follow-Up

A Patient-Level Data Meta-analysis of the Abscopal Effect

Purpose

The abscopal effect is defined when a form of local therapy causes tumor regression of both the target lesion and any untreated tumors. Herein cases of the abscopal effect were systematically reviewed and a patient-level data analysis was performed for clinical predictors of both duration of response and survival.

Methods and Materials

The Population, Intervention, Control, Outcome, Study (PICOS) design approach, Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) literature selection process, and Meta-analysis of Observational Studies in Epidemiology (MOOSE) were used to find articles published before September 2019 in MEDLINE/PubMed and Google Scholar. Inclusion criteria were (1) population: patients with reported abscopal response; (2) intervention: documented treatment(s); (3) control: none; (4) outcomes: overall and progression-free survival; and (5) setting: retrospective case reports. Time from treatment until abscopal response and time from abscopal response until progression/death were calculated. Univariate and multivariate analyses were conducted for survival outcomes.

Results

Fifty studies (n = 55 patients) were included. Median age was 65 years (interquartile range [IQR], 58-70) and 62% were male. Fifty-four (98%) patients received radiation therapy, 34 (62%) received radiation therapy alone, 5 (9.1%) underwent surgery, 4 (7.3%) received chemotherapy, and 11 (20%) received immunotherapy. Median total dose was 32 Gy (IQR, 25.5-48 Gy) and median dose per fraction was 3 Gy (IQR, 2-7.2). Median time until abscopal response was 4 months (IQR, 1-5; min 0.5, max 24). At 5 years, overall survival was 63% and distant progression-free survival was 45%. No variables had statistical significance in predicting duration of response or survival.

Conclusions

Almost all reported cases of the abscopal response are after radiation therapy; however, there are no known predictors of duration of response or survival in this population.

Abscopal Effects in Metastatic Cancer: Is a Predictive Approach Possible to Improve Individual Outcomes?

Patients with metastatic cancers often require radiotherapy (RT) as a palliative therapy for cancer pain. RT can, however, also induce systemic antitumor effects outside of the irradiated field (abscopal effects) in various cancer entities. The occurrence of the abscopal effect is associated with a specific immunological activation in response to RT-induced cell death, which is mainly seen under concomitant immune checkpoint blockade. Even if the number of reported apscopal effects has increased since the introduction of immune checkpoint inhibition, its occurrence is still considered rare and unpredictable. The cases reported so far may nevertheless allow for identifying first biomarkers and clinical patterns. We here review biomarkers that may be helpful to predict the occurrence of abscopal effects and hence to optimize therapy for patients with metastatic cancers.

Novel Insights into the Immunotherapy of Soft Tissue Sarcomas: Do We Need a Change of Perspective?

Soft tissue sarcomas (STSs) are rare mesenchymal tumors. With more than 80 histological subtypes of STSs, data regarding novel biomarkers of strong prognostic and therapeutic value are very limited. To date, the most important prognostic factor is the tumor grade, and approximately 50% of patients that are diagnosed with high-grade STSs die of metastatic disease within five years. Systemic chemotherapy represents the mainstay of metastatic STSs treatment for decades but induces response in only 15–35% of the patients, irrespective of the histological subtype. In the era of immunotherapy, deciphering the immune cell signatures within the STSs tumors may discriminate immunotherapy responders from non-responders and different immunotherapeutic approaches could be combined based on the predominant cell subpopulations infiltrating the STS tumors. Furthermore, understanding the immune diversity of the STS tumor microenvironment (TME) in different histological subtypes may provide a rationale for stratifying patients according to the TME immune parameters. In this review, we introduce the most important immune cell types infiltrating the STSs tumors and discuss different immunotherapies, as well as promising clinical trials, that would target these immune cells to enhance the antitumor immune responses and improve the prognosis of metastatic STSs patients.

Durability of response in metastatic melanoma patients after combined treatment with radiation therapy and ipilimumab

AIM

We previously reported a prospective trial evaluating the safety and efficacy of combining ipilimumab and radiation therapy in patients with metastatic melanoma. Herein, we provide a long-term update on patients with complete response (CR) or partial response (PR).

PATIENTS & METHODS

We continued to follow these patients with serial imaging including computed tomography, PET or MRI.

RESULTS

Two of the three patients with CR are still alive and without evidence of melanoma but with chronic treatment-induced hypophysitis. The third patient died of hepatocellular carcinoma, but with no evidence of melanoma. Among the three patients with PR, two achieved CR after pembrolizumab monotherapy.

CONCLUSION

This long-term follow up reveals the striking durability of the CRs, which appears to correlate with a grade 2-3 hypophysitis.

Preferences for Immunotherapy in Melanoma: A Systematic Review

BACKGROUND

Immunotherapy improves overall survival for patients with metatstatic melanoma and improves recurrence-free survival in the adjuvant setting, but is costly and has adverse effects. Little is known about the preferences of patients and clinicians regarding immunotherapy. This study aimed to identify factors important to patients and clinicians when deciding about immunotherapy for stages 2-4 melanoma.

METHODS

This study searched the Medline, EMBASE, ECONLIT, PsychINFO, and COCHRANE Systematic Reviews databases from inception to June 2018 for immunotherapy choice and preference studies. Findings were tabulated and summarized, and study reporting was assessed against recommended checklists.

RESULTS

This investigation identified eight studies assessing preferences for melanoma treatment; four studies regarding nivolumab, pembrolizumab, or ipilimumab; and four studies regarding interferon conducted in the United States, Germany, and Australia. The following 10 factors were important to decision-making: overall survival, recurrence-free survival, treatment side effects, dosing regimen, patient or payer cost, patient age, clinician or family/friend treatment recommendation, quality of life, and psychosocial effects. Overall survival was the most important factor for all respondents. The patients judged severe toxicities to be tolerable for small survival gains. The description of information about treatment harms and benefits was limited in most studies.

CONCLUSIONS

Overall survival was of primary importance to patients and clinicians considering immunotherapy. Impaired quality of life due to adverse effects appeared to be a second-order consideration. Future research is required to determine preferences for contemporary combination therapies, extended treatment durations, and avoidance of chronic side effects.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number CRD42018095899.