Adding Concomitant Chemotherapy to Postoperative Radiotherapy in Oral Cavity Carcinoma with Minor Risk Factors: Systematic Review of the Literature and Meta-Analysis.

When presenting with major pathological risk factors, adjuvant radio-chemotherapy for oral cavity cancers (OCC) is recommended, but the addition of chemotherapy to radiotherapy (POCRT) when only minor pathological risk factors are present is controversial. A systematic review following the PICO-PRISMA methodology (PROSPERO registration ID: CRD42021267498) was conducted using the PubMed, Embase, and Cochrane libraries. Studies assessing outcomes of POCRT in patients with solely minor risk factors (perineural invasion or lymph vascular invasion; pN1 single; DOI ≥ 5 mm; close margin < 2−5 mm; node-positive level IV or V; pT3 or pT4; multiple lymph nodes without ENE) were evaluated. A meta-analysis technique with a single-arm study was performed. Radiotherapy was combined with chemotherapy in all studies. One study only included patients treated with POCRT. In the other 12 studies, patients were treated with only PORT (12,883 patients) and with POCRT (10,663 patients). Among the patients treated with POCRT, the pooled 3 year OS rate was 72.9% (95%CI: 65.5−79.2%); the pooled 3 year DFS was 70.9% (95%CI: 48.8−86.2%); and the pooled LRFS was 69.8% (95%CI: 46.1−86.1%). Results are in favor of POCRT in terms of OS but not significant for DFS and LRFS, probably due to the heterogeneity of the included studies and a combination of different prognostic factors.

Can Radiotherapy Empower the Host Immune System to Counterattack Neoplastic Cells? A Systematic Review on Tumor Microenvironment Radiomodulation.

Despite the rising evidence in favor of immunotherapy (IT), the treatment of oncological patients affected by so-called "cold tumors" still represents an open issue. Cold tumors are characterized by an immunosuppressive (so-called cold) tumor microenvironment (TME), which favors host immune system suppression, cancer immune-escape, and a worse response to IT. However, the TME is not a static element, but dynamically mutates and can be changed. Radiotherapy (RT) can modulate a cold microenvironment, rendering it better at tumor killing by priming the quiescent host immune system, with a consequent increase in immunotherapy response. The combination of TME radiomodulation and IT could therefore be a strategy for those patients affected by cold tumors, with limited or no response to IT. Thus, this review aims to provide an easy, rapid, and practical overview of how RT could convert the cold TME and why cold tumor radiomodulation could represent an interesting strategy in combination with IT.