Comparison of Clinical Outcomes, Pathologic Characteristics, and Immune-Related Features of Postradiation vs Sporadic Oral Cavity Squamous Cell Carcinoma.

Importance: Postradiation oral cavity squamous cell carcinoma (OCSCC) is a common secondary malignant neoplasm affecting survivors of head and neck cancer who underwent radiotherapy. The clinical, pathologic, and immune-related features of postradiation OCSCC are poorly characterized, and treatment options are limited because of surgical difficulty and high morbidity associated with reirradiation. Objective: To determine whether postradiation OCSCC has distinctive clinical, pathologic, and immune-related features compared with demographic-matched sporadic OCSCC. Design, Setting, and Participants: This retrospective matched cohort study was conducted at a single tertiary oncology center in Hong Kong. Participants included consecutive patients with OCSCC diagnosed between 2000 and 2020. Patients with postradiation OCSCC were matched with patients with sporadic OCSCC using age, year of diagnosis, sex, and anatomic subsites. Data analysis was performed from July to December 2022. Exposure: Head and neck irradiation involving the oral cavity before the diagnosis of OCSCC. Main Outcomes and Measures: The primary outcomes were relapse pattern, survival, and causes of death. Pathologic features; immunohistochemical staining for programmed death-ligand 1, PD-1, MSH6, PMS2, FOXP3, and Ki67; and mRNA expression of 31 immune-related genes were also analyzed. Results: A total of 173 patients, 60 with postradiation OCSCC (median [IQR] age, 63.8 [53.0-71.7] years; 43 men [71.7%]) and 113 with sporadic OCSCC (median [IQR] age, 64.4 [52.8-70.6] years; 83 men [73.5%]), were included. Patients with postradiation OCSCC had a higher proportion of N0 disease than those with sporadic OCSCC (50 patients [83.3%] vs 56 patients [49.6%]). With a median (IQR) follow-up of 10.2 (1.2-20.5) years, the 10-year relapse-free survival rates were lower in patients with postradiation OCSCC than sporadic OCSCC (29.6% [95% CI, 17.1%-43.2%] vs 52.4% [95% CI, 41.8%-62.0%]; P = .04), and the same was true for overall survival (30.5% [95% CI, 17.6%-44.4%] vs 52.3% [95% CI, 41.4%-62.1%]; P = .03). All relapses in patients with postradiation OCSCC were locoregional, whereas 35.2% of relapses (12 of 34 patients) in patients with sporadic OCSCC were distant. Despite similar 10-year disease-specific survival rates between the 2 groups (68.8% [95% CI, 55.8%-81.0%] vs 67.1% [95% CI, 57.5%-76.5%]; P = .91), patients with postradiation OCSCC had excess mortality due to pneumonia and cerebrovascular events. Postradiation OCSCC exhibited more adverse pathologic features (perineural invasion, worse pattern of invasion, and tumor budding), higher PD-1 expression, and higher gene expression of CD4 and TGF-ß compared with sporadic OCSCC. Conclusions and Relevance: This retrospective matched cohort study found distinctive pathologic characteristics and relapse patterns of postradiation OCSCC compared with sporadic OCSCC, which may be attributable to the lack of adjuvant radiotherapy, aggressive biologic phenotype, and different host immune response. Further exploration of the role of immune checkpoint therapy may be justified.

Cranial neuropathies in advanced nasopharyngeal carcinoma: Neurological recovery after modern radiotherapy and systemic chemotherapy.

OBJECTIVES: Cranial neuropathy is a common presenting symptom of advanced T4 nasopharyngeal carcinoma (NPC). Data on neurological outcomes after modern intensity-modulated radiotherapy (IMRT) and chemotherapy are scarce. MATERIALS AND METHODS: Case records of consecutive T4 NPC patients who received definitive IMRT in two tertiary oncology centers in 2004-2019 were reviewed. Patterns of cranial neuropathies at disease presentation were recorded. Time to neurological recovery and the rate of subsequent re-palsy were estimated by the Kaplan-Meier method. Clinical predictors were analyzed using multivariable Cox regression. RESULTS: During the study period, 257 T4 NPC patients presented with 504 individual cranial neuropathies. The median time from neuropathy onset to NPC diagnosis was two months (IQR, 1-4 months). Cranial nerves (CN) VI (56.4%), V2 (47.9%), and V3 (29.2%) were most frequently involved. At a median follow-up of 6.4 years, the crude partial and full recovery rates of neuropathies were 111 (22%) and 289 (57.3%), respectively. CN III, IV, and VI had the highest 5-year full recovery rate (72.7%), followed by CN V1-3 (60.3%), XII (48.6%), and II (18.2%) (p < 0.001). Positive smoking history, optic nerve involvement, and longer duration of neuropathy were independent negative predictors for neurological recovery. After full recovery, re-palsy was observed in 6.9% (20/289) of the nerves, 60% of which co-occurred with local NPC recurrences. CONCLUSION: Durable recovery of most cranial neuropathies in advanced T4 NPC was observed in the era of modern IMRT and effective systemic chemotherapy. Both patient and disease factors affected the chance of neurological recovery. Re-palsy of recovered nerves should prompt careful evaluation for local recurrence.

The treatment landscape of advanced angiosarcoma in Asia-A multi-national collaboration from the Asian Sarcoma Consortium.

Angiosarcoma (AS) is a rare disease with a dismal prognosis. The treatment landscape and prognostic factors for advanced AS, including locally advanced, unresectable, and metastatic disease remain elusive. The Asian Sarcoma Consortium is an international collaborative effort to understand the sarcoma treatment landscape in Asia. We undertook a retrospective chart review of AS patients seen in 8 sarcoma academic centers across Asia. Patients with complete clinical, treatment, and follow-up data were enrolled. Overall, 276 advanced AS patients were included into this study; 84 (30%) of the patients had metachronous metastatic AS. The median age was 67 y; primary sites of AS was cutaneous in 55% and visceral in 45% of patients. In total, 143 (52%) patients received at least 1 line of systemic chemotherapy. The most common first-line chemotherapy regimen used was paclitaxel (47.6%) followed by liposomal doxorubicin (19.6%). The median overall survival (OS) was 7.8 mo. Significant prognostic factors for OS included age > 65 (hazard ratio (HR) 1.54, P = .006), male gender (HR 1.39, P = .02), and a cutaneous primary AS site (HR 0.63, P = .004). The median progression-free survival (PFS) for first-line chemotherapy was 3.4 mo. PFS for single vs combination or paclitaxel vs liposomal doxorubicin chemotherapy regimens were comparable. This study provides an insight into the treatment patterns and prognostic factors of advanced AS patients in Asia. Prognosis of advanced AS remains poor. Data from this study serve as a benchmark for future clinical study design.

Application of hypoglossal nerve constraint in definitive radiotherapy for nasopharyngeal carcinoma: A dosimetric feasibility study.

PURPOSE: Radiation-induced hypoglossal nerve palsy is an infrequent but debilitating late complication after definitive radiotherapy for head and neck cancers. D1cc < 74 Gy (equivalent dose in 2 Gy fractions, EQD2) has been proposed as a potential dose constraint that limits 8-year palsy risk to < 5%. This study sets to perform detailed dosimetric assessments on the applicability of this novel dose constraint in advanced nasopharyngeal carcinoma (NPC). MATERIALS AND METHODS: This is a retrospective single-institution dosimetry study. NPC radiotherapy plans were identified from an institutional database, with an aim to select 10 eligible cases. Bilateral hypoglossal nerves were retrospectively contoured following a standard atlas. Cases with either one, or both, hypoglossal nerves D1cc exceeded 74 Gy EQD2 were included. Dosimetry of hypoglossal nerves, planning target volumes (PTV) and normal structures before and after application of the new hypoglossal nerve constraint were compared and analyzed. RESULTS: Ten NPC cases were replanned. All hypoglossal nerve contours overlapped with high-dose PTV, predominantly at regions of gross nodal diseases. D1cc in 15 out of 20 hypoglossal nerves exceeded 74G y EQD2 at initial plans. All nerves fulfilled the pre-specified constraint of 74Gy EQD2 after re-plan. Median hypoglossal nerve D1cc reduced from 74.8Gy (range, 74.1 to 77.4Gy) to 73.5Gy (range, 72.4 to 74.0Gy) (p < 0.001), corresponded to a projected reduction in 8-year palsy risk from 5%-14% to 3%-5%. PTV V100 was maintained above 95% in all cases. Dose increments in near-maximum (D2) and decrements in near-minimum (D98) were < 1 Gy. Safety dosimetric parameters of standard head and neck organs-at-risk showed no significant changes. CONCLUSIONS: Hypoglossal nerve D1cc < 74 Gy EQD2 is a dosimetrically feasible constraint in definitive radiotherapy for NPC. Tumor target coverage and normal organ dosimetry were not compromised with its usage. Its routine application should be considered in definitive radiotherapy for head and neck cancers.

Radiation-induced hypoglossal nerve palsy after definitive radiotherapy for nasopharyngeal carcinoma: Clinical predictors and dose-toxicity relationship.

BACKGROUND AND PURPOSE: Radiation-induced hypoglossal nerve palsy is a debilitating and irreversible late complication after definitive radiotherapy for nasopharyngeal carcinoma (NPC) and other skull base tumors. This study sets to evaluate its incidence and clinical predictive factors, and to propose relevant dosimetric constraints for this structure to guide radiotherapy planning. MATERIALS AND METHODS: We undertook a retrospective review of 797 NPC patients who underwent definitive intensity-modulated radiotherapy (IMRT) between 2003 and 2011. Cumulative incidence and clinical predictors for radiation-induced hypoglossal nerve palsy were evaluated. Archived radiotherapy plans were retrieved and 330 independent hypoglossal nerves were retrospectively contoured following standardized atlas. Optimal threshold analyses of dosimetric parameters (Dmax, D0.5cc, D1cc, D2cc, Dmean) were conducted using receiver operating characteristic curves. Normal tissue complication probability was generated with logistic regression modeling. RESULTS: With a median follow-up of 8.1 years, sixty-nine (8.7%) patients developed radiation-induced hypoglossal nerve palsy. High radiotherapy dose, premorbid diabetes, advanced T-stage and radiological hypoglossal canal involvement were independent clinical risk factors. Maximum dose received by 1 cc volume (D1cc) was the best predictor for the development of radiation-induced nerve palsy (AUC = 0.826) at 8 years after IMRT. Hypoglossal nerves with D1cc of 74 Gy EQD2 had an estimated palsy risk of 4.7%. Nerves with D1cc <74 Gy EQD2 had significantly lower risk of palsy than those ≥74 Gy EQD2 (2.4% vs 20.8%, p <0.001). CONCLUSION: Incidence of radiation-induced hypoglossal nerve palsy was high after definitive IMRT for NPC. D1cc <74 Gy EQD2 can serve as a useful dose constraint to adopt during radiotherapy planning to limit palsy risk to <5% at 8 years after IMRT.