Cholangiocarcinoma: Recent Advances in Molecular Pathobiology and Therapeutic Approaches

Cholangiocarcinomas (CCA) pose a complex challenge in oncology due to diverse etiologies, necessitating tailored therapeutic approaches. This review discusses the risk factors, molecular pathology, and current therapeutic options for CCA and explores the emerging strategies encompassing targeted therapies, immunotherapy, novel compounds from natural sources, and modulation of gut microbiota. CCA are driven by an intricate landscape of genetic mutations, epigenetic dysregulation, and post-transcriptional modification, which differs based on geography (e.g., for liver fluke versus non-liver fluke-driven CCA) and exposure to environmental carcinogens (e.g., exposure to aristolochic acid). Liquid biopsy, including circulating cell-free DNA, is a potential diagnostic tool for CCA, which warrants further investigations. Currently, surgical resection is the primary curative treatment for CCA despite the technical challenges. Adjuvant chemotherapy, including cisplatin and gemcitabine, is standard for advanced, unresectable, or recurrent CCA. Second-line therapy options, such as FOLFOX (oxaliplatin and 5-FU), and the significance of radiation therapy in adjuvant, neoadjuvant, and palliative settings are also discussed. This review underscores the need for personalized therapies and demonstrates the shift towards precision medicine in CCA treatment. The development of targeted therapies, including FDA-approved drugs inhibiting FGFR2 gene fusions and IDH1 mutations, is of major research focus. Investigations into immune checkpoint inhibitors have also revealed potential clinical benefits, although improvements in survival remain elusive, especially across patient demographics. Novel compounds from natural sources exhibit anti-CCA activity, while microbiota dysbiosis emerges as a potential contributor to CCA progression, necessitating further exploration of their direct impact and mechanisms through in-depth research and clinical studies. In the future, extensive translational research efforts are imperative to bridge existing gaps and optimize therapeutic strategies to improve therapeutic outcomes for this complex malignancy.

Polymorphous Low Grade Adenocarcinoma of the Parotid in a Teenager

INTRODUCTION

Polymorphous low grade adenocarcinoma (PLGA) is a rare salivary gland neoplasm with an indolent course. It occurs primarily in the minor salivary glands but can rarely occur in the major salivary glands. It usually occurs in the fifth to seventh decades of life with female preponderance.

CASE REPORT

A 16-year-old male presented with recurrent painless swelling in the right preauricular region and with a history of surgical intervention at the same site in the past. His histopathology report was suggestive of pleomorphic adenoma. The swelling recurred after one year of excision and a superficial parotidectomy was performed. The detailed histopathological examination was suggestive of Polymorphous low grade adenocarcinoma. In view of close margins, the patient was given adjuvant radiotherapy. Thirty-three months post-surgery, he is alive and disease-free. We describe a rare case of PLGA of the parotid gland in a teenager with its clinical characteristics, histopathological features, and treatment.

CONCLUSION

The occurrence of PLGA in the parotid gland is rare with only a few cases reported in literature. The diagnosis of PLGA is challenging due to morphological diversity.

Extraosseous Ewing's Sarcoma of the Parapharyngeal Space - A Rare Entity - with Review of Literature

INTRODUCTION

Extraosseous Ewing's sarcoma (EES) of the head and neck region is a rare occurrence, and Ewing's sarcoma of the parapharyngeal space is even rarer. To the best of our knowledge, only three cases of EES of the parapharyngeal space have been reported in the literature.

CASE REPORT

We report a rare case of EES of the parapharyngeal space in an 8-year-old girl. She presented with complaints of earache, difficulty in breathing and swallowing and bleeding from the mouth. Investigations revealed a large parapharyngeal mass causing narrowing of the nasopharyngeal and oropharyngeal airway with skeletal and lung metastasis. Biopsy from the parapharyngeal mass was suggestive of malignant small round cell tumor. The patient was treated with chemotherapy and radiotherapy, but developed brain metastasis and succumbed to disease approximately 1 year after diagnosis. Herein, we describe the characteristic clinicopathological features and treatment with a comprehensive review of the literature.

CONCLUSION

EES in this unusual location behaves aggressively, with a high rate of recurrence and distant metastasis. Aggressive multimodal treatment comprising of multi-agent chemotherapy, surgical resection if feasible, and radiotherapy should be considered.

Simultaneous Integrated Boost (SIB) Versus Sequential Boost in Anal Cancer Patients: A Single-Center Experience

PURPOSE

Concurrent chemoradiation is the standard of care for the treatment of anal cancer. Radiation can be delivered by sequential or simultaneous integrated boost (SIB) approach. The present study was conducted to compare the treatment outcomes and toxicity profile of patients with anal cancer treated with sequential boost and SIB approach.

METHODS

A single-institution retrospective analysis of patients with squamous cell carcinoma of the anal canal treated between 2019 and 2022 with radical chemoradiation was performed. The sequential boost schedule consisted of 45 Gy in 25 fractions (1.8 Gy daily) to the gross tumor, nodes, and elective nodal volume, followed by a 9 Gy in five fractions boost to the gross disease. Patients receiving SIB were treated as per RTOG 0529 protocol. In both the groups, patients were treated with volumetric modulated arc therapy (VMAT). The two groups were compared in terms of overall survival (OS), colostomy-free survival (CFS), relapse-free survival (RFS), and acute toxicity profile. p-values < 0.05 were considered statistically significant.

RESULTS

The patient and disease characteristics in both treatment arms were comparable. The only difference was a significantly longer overall treatment time of ≥ 50 days in the sequential arm (77.8% vs 43.8%, p = 0.04). The median follow-up was 18 months. The 2-year CFS was 80% in sequential vs 87.5% at 2 years for the SIB arm, 2-year OS 83.3% vs 58.6%, and 2-year RFS was 38.9% vs 41.7%, respectively. A total of 14 (77.8%) in sequential and 8 (50%) in the SIB arm had disease relapse. On univariate analysis, the involved pelvic lymph node significantly affected OS (HR 10.45, p = 0.03) while inguinal lymph node involvement adversely affected RFS (HR 6.16, p = 0.02). The most common acute toxicity was radiation-induced dermatitis, 15 (83.4%; 5 grade II, 10 grade III) in sequential vs 7 (43.8%; 3 each grade II and III) in the SIB group followed by hematological (61.1% vs 68.75%). However, the incidence of overall acute toxicities was significantly less in the SIB arm (p = 0.006).

CONCLUSION

Our study showed that concurrent chemoradiation with the SIB-VMAT approach is well tolerated in patients of anal carcinoma and resulted in lesser treatment interruptions and comparable outcomes as compared to the sequential approach. Our results warrant further evaluation in a prospective study.