The Risk of Second Malignant Tumors after Definitive Treatment of Nasopharyngeal Carcinoma: Three Case Reports and Literature Review

Abstract

Introduction: Patients with head and neck squamous cell carcinoma (HNSCC) have an increased incidence of developing second malignant tumors (SMTs). This may possibly be explained by the concept of “field cancerization” or “condemned mucosa syndrome”, implying the importance of other risk factors like smoking, alcohol consumption, genetic factors and viral infections. However, risk factors for SMTs have not been documented well, especially in nasopharyngeal carcinoma (NPC).

Objective: Evaluate the presence of risk factors in the development of SMTs after the treatment of NPC at our institution after a 6-year follow up.

Methods: In this study, we retrospectively analyzed 63 patients with pathologically confirmed diagnosis of non-metastatic NPC from June 2009 to June 2015 treated with curative intent using EBRT (IMRT/3D) with concurrent chemotherapy for the development of SMTs. Apart from our data, literature review on the topic showed an additional 1970 patients who were also analyzed.

Results: After a median follow up of 56 months (24–96 months), 2 patients were diagnosed with SMTs of tongue after 5 years and 1 patient developed esthesioneuroblastoma of right nasal cavity 3 years later in the radiation field. Both patients with SMTs in the tongue were diagnosed with Stage 1 SCC of the tongue, in the previously irradiated field and both were treated with HDR Brachytherapy with a dose of 36 Gy in twice daily fractionated schedule for 5–6 days. The third patient diagnosed with esthesioneuroblastoma of right nasal cavity was treated with complete excision of the mass. 60 out of the 1970 patients from the literature reviewed had developed SMTs at various sites.

Conclusions: In patients with NPC, radiation therapy is probably a potential risk factor for developing SMTs, apart from other independent risk factors like tobacco and alcohol. SMTs can develop as early as 3 years after the completion of treatment and hence warrant close follow-up.

Keywords: Second malignancy, nasopharyngeal carcinoma, radiation therapy

Cite this Article

Devika Sunil, Ashwini Laksmaiah, Dinesh Makuny et al. The Risk of Second Malignant Tumors after Definitive Treatment of Nasopharyngeal Carcinoma: Three Case Reports and Literature Review. Research & Reviews: Journal of Oncology and Hematology. 2017; 6(2): 15–20p.