Abscopal Response in Metastatic Melanoma: Real-World Data of a Retrospective, Multicenter Study

Abscopal Effects and Immunomodulation in Skin Cancer Therapy

Radiation therapy (RT) is a crucial modality in cancer treatment, functioning through direct DNA damage and immune stimulation. However, RT's effects extend beyond targeted cells, influencing neighboring cells through the bystander effect (ByE) and distant sites via the abscopal effect (AbE). The AbE, first described by Mole in 1953, encompasses biological reactions at sites distant from the irradiation field. While RT can enhance antitumor immune responses, it may also contribute to an immunosuppressive microenvironment. To address this limitation, combining RT with immune checkpoint inhibitors (ICIs) has gained renewed interest, aiming to amplify antitumor immune responses. Evidence of AbEs has been observed in various metastatic or advanced cutaneous cancers, including melanoma, basal cell carcinoma, cutaneous lymphoma, Merkel cell carcinoma, and cutaneous squamous cell carcinoma. Clinical studies suggest combining RT with ICIs targeting CTLA-4 and PD-1/PD-L1 may enhance AbE incidence in these cancers. This review primarily explores the current understanding of AbEs in skin cancers, briefly acknowledging the ByE focusing on combining RT with immunomodulation. It focuses on proposed mechanisms, preclinical and clinical evidence, challenges in clinical translation, and future directions for harnessing AbEs in managing advanced skin malignancies. Alternative modalities for inducing abscopal-like responses are also explored. While promising, challenges remain in consistently reproducing AbEs in clinical practice, necessitating further research to optimize treatment combinations, timing, and patient selection.

Carcinoma lung with cutaneous metastasis: experience from an Indian institute

Background

Majority of lung cancer patients are presented with metastatic disease. However, cutaneous metastasis (CM) from lung carcinoma is a rare entity with very few case reports published in the Indian background. Moreover, outcome in these patients is dismal and no standard therapeutic approaches are there. Thus, a long-term analysis from a single institute in this infrequent occurrence holds scientific importance. The purpose of this study was to describe the clinico-demographic profile of patients having CM with lung primary and also to evaluate the survival outcomes in these patients.

Materials and methods

This was a retro-prospective study conducted over 5-year time period in an academic institute of India. Records of all histopathologically confirmed lung cancer patients were reviewed and patients having biopsy-proven CM were included in this analysis. Permission from Institutional Ethics Committee and informed consent from all the patients were taken. Data of these patients were collected and analysed using standard statistical software.

Results

Total of 25 cases of biopsy-proven CM were found in the stipulated time period. Mean age of patients was 57.6 years with high male predominance. Anterior chest wall was the most common site of skin involvement and squamous cell carcinoma was the most common primary histopathology. Overall, median survival was 4.9 months.

Conclusion

Once CM developed, survival of lung carcinoma patients become dismal. Goal of the treatment will be to palliate and to improve quality of life in these patients. Understanding the clinical pattern and demographic profile of these patients will guide a standard treatment approach.

Open-label, phase II study of talimogene laherparepvec plus pembrolizumab for the treatment of advanced melanoma that progressed on prior anti-PD-1 therapy: MASTERKEY-115

BACKGROUND

Treatment options for immunotherapy-refractory melanoma are an unmet need. The MASTERKEY-115 phase II, open-label, multicenter trial evaluated talimogene laherparepvec (T-VEC) plus pembrolizumab in advanced melanoma that progressed on prior programmed cell death protein-1 (PD-1) inhibitors.

METHODS

Cohorts 1 and 2 comprised patients (unresectable/metastatic melanoma) who had primary or acquired resistance, respectively, and disease progression within 12 weeks of their last anti-PD-1 dose. Cohorts 3 and 4 comprised patients (resectable disease) who underwent complete surgery, received adjuvant anti-PD-1, and experienced recurrence. Cohort 3 were disease-free for < 6 months and cohort 4 for ≥ 6 months after starting the adjuvant anti-PD-1 therapy and before confirmed recurrence. The primary endpoint was objective response rate (ORR) per RECIST v1.1. Secondary endpoints included complete response rate (CRR), disease control rate (DCR) and progression-free survival (PFS) per RECIST v1.1 and irRC-RECIST, and safety.

RESULTS

Of the 72 enrolled patients, 71 were treated. The ORR (95% CI) was 0%, 6.7% (0.2-32.0), 40.0% (16.3-67.7), and 46.7% (21.3-73.4) in cohorts 1-4, respectively; iORR was 3.8% (0.1-19.6), 6.7% (0.2-32.0), 53.3% (26.6-78.7), and 46.7% (21.3-73.4). iCRR was 0%, 0%, 13.3%, and 13.3%. Median iPFS (months) was 5.5, 8.2, not estimable [NE], and NE for cohorts 1-4, respectively; iDCR was 50.0%, 40.0%, 73.3%, and 86.7%. Treatment-related adverse events (TRAEs), grade ≥ 3 TRAEs, serious AEs, and fatal AEs occurred in 54 (76.1%), 9 (12.7%), 24 (33.8%), and 10 (14.1%) patients, respectively.

CONCLUSION

T-VEC-pembrolizumab demonstrated antitumor activity and tolerability in PD-1-refractory melanoma, specifically in patients with disease recurrence on or after adjuvant anti-PD-1.

TRIAL REGISTRATION

ClinicalTrials.gov identifier - NCT04068181.

Strategies for overcoming tumour resistance to immunotherapy: harnessing the power of radiation therapy

Immune checkpoint inhibitors (ICI) have revolutionized cancer treatment; yet their efficacy remains variable across patients. This review delves into the intricate interplay of tumour characteristics contributing to resistance against ICI therapy and suggests that combining with radiotherapy holds promise. Radiation, known for its ability to trigger immunogenic cell death and foster an in situ vaccination effect, may counteract these resistance mechanisms, enhancing ICI response and patient outcomes. However, particularly when delivered at high-dose, it may trigger immunosuppressive mechanism and consequent side-effects. Notably, low-dose radiotherapy (LDRT), with its capacity for tumour reprogramming and reduced side effects, offers the potential for widespread application. Preclinical and clinical studies have shown encouraging results in this regard.

Radiotherapy in the management of lung oligometastases

In recent years, the development of both medical imaging and new systemic agents (targeted therapy and immunotherapy) have revolutionized the field of oncology, leading to a new entity: oligometastatic disease. Adding local treatment of oligometastases to systemic treatment could lead to prolonged survival with no significant impact on quality of life. Given the high prevalence of lung oligometastases and the new systemic agents coming with increased pulmonary toxicity, this article provides a comprehensive review of the current state-of-art for radiotherapy of lung oligometastases. After reviewing pretreatment workup, the authors define several radiotherapy regimen based on the localization and size of the oligometastases. A comment on the synergistic combination of medical treatment and radiotherapy is also made, projecting on future steps in this specific clinical setting.

The abscopal effect of immune-radiation therapy in recurrent and metastatic cervical cancer: a narrative review

Despite human papillomavirus vaccination and screening, in about 5% of cases, cervical cancer (CC) is discovered at an initial metastatic stage. Moreover, nearly one-third of patients with locally advanced CC (LACC) will have a recurrence of their disease during follow-up. At the stage of recurrent or metastatic CC, there are very few treatment options. They are considered incurable with a very poor prognosis. For many years, the standard of care was the combination of platinum-based drug and paclitaxel with the possible addition of bevacizumab. The most recent years have seen the development of the use of immune checkpoint inhibitors (ICIs) (pembrolizumab, cemiplimab and others) in patients with CC. They have shown long term responses with improved overall survival of patients in 1st line (in addition to chemotherapy) or 2nd line (as monotherapy) treatment. Another emerging drug is tisotumab vedotin, an antibody-drug conjugate targeting tissue factor. Radiation therapy (RT) often has a limited palliative indication in metastatic cancers. However, it has been observed that RT can induce tumor shrinkage both in distant metastatic tumors beyond the radiation field and in primary irradiated tumors. This is a rarely observed phenomenon, called abscopal effect, which is thought to be related to the immune system and allows a tumor response throughout the body. It would be the activation of the immune system induced by the irradiation of cancer cells that would lead to a specific type of apoptosis, the immunogenic cell death. Today, there is a growing consensus that combining RT with ICIs may boost abscopal response or cure rates for various cancers. Here we will review the potential abscopal effect of immune-radiation therapy in metastatic cervical cancer.

Abscopal Effect on Bone Metastases from Solid Tumors: A Systematic Review and Retrospective Analysis of Challenge within a Challenge

BACKGROUND

Abscopal effect (AE) describes the ability of radiotherapy (RT) to induce immune-mediated responses in nonirradiated distant metastasis. Bone represents the third most frequent site of metastasis and an immunologically favorable environment for the proliferation of cancer cells. We revised the literature, searching documented cases of AE involving bone metastases (BMs) and evaluated the incidence of AE involving BMs in patients requiring palliative RT on BMs or non-BMs treated at our department.

METHODS

Articles published in the PubMed/MEDLINE database were selected using the following search criteria: ((abscopal effect)) AND ((metastases)). Patients with BMs, who underwent performed bone scintigraphy before and at least 2-3 months after RT, were selected and screened between January 2015 and July 2022. AE was defined as an objective response according to the scan bone index for at least one nonirradiated metastasis at a distance > 10 cm from the irradiated lesion. The primary endpoint was the rate of AE on BMs.

RESULTS

Ten cases experiencing AE of BMs were identified from the literature and eight among our patients.

CONCLUSIONS

The analysis performed here suggests the use of hypofractionated radiotherapy as the only triggering factor for AE of BMs through the activation of the immune response.