Leiomyosarcoma frequently presents in older patients at high tumor grade
MedWire News: Half of patients who present with leiomyosarcoma (LMS) of the head and neck are older than 70 years, many of whom have high-grade, poorly differentiated tumors that are best treated with surgery, a study shows.
The findings provide important data, currently lacking, on this rare tumor type, which accounts for just 1% of all malignant neoplasms in the head and neck area. LMS is derived from smooth muscle, and can be either cutaneous (derived from arrector pili muscles of hair follicles) or subcutaneous (derived from vascular smooth muscle).
"LMS of the head and neck is an extremely rare entity that because of its infrequency has been associated with both delayed diagnosis and misdiagnosis," comment study co-author Nitin Pagedar (University of Iowa Hospitals and Clinics, Iowa City, USA) and colleagues.
To better characterize the disease, Pagedar et al reviewed the Surveillance, Epidemiology, and End Results (SEER) database, which includes 17 registries that together cover 26% of the US population. They identified 578 patients with LMS diagnosed between 1973 and 2007.
The mean age at diagnosis was 64 years and the frequency of LMS increased with age: 50% of the patients were older than 70 years, and 75% were older than 50 years, at the time of diagnosis.
The primary site of 83% of the tumors was the skin and soft tissue of the head and neck, with a minority found in mucosal sites and salivary glands.
Only a few (16.4%) tumors were well differentiated, with most moderately (44.4%) or poorly (39.2%) differentiated. Also, most (87%) tumors were smaller than 5 cm in greatest dimension and localized (61%), with a substantial minority demonstrating deep extension (39%), and only 2% demonstrating lymphatic spread.
The median observed survival in the cohort was 84.7 months, with 56.4% of the patients surviving 5 years. The 5-year disease-specific survival for well-differentiated tumors was 87.6% compared with 85.7% for moderately differentiated tumors, and 52.7% for poorly differentiated tumors.
Patients who received surgery alone showed improved survival compared with those who received radiotherapy alone or adjuvant radiotherapy (median survival, 100 vs 16 and 64.2 months, respectively).
Discussing their study, the researchers note divergent findings of a prior review of LMS showing that the most common location of the primary lesion was the oral cavity followed by the paranasal sinuses.
"This discrepancy could arise from limitations of the SEER database and poor classification of primary tumor sites, or it could be attributable to the comparably larger number of patients in our cohort," they comment.
The findings are published in the Archives of Otolaryngology, Head and Neck Surgery.
By Andrew Czyzewski