Prognostic impact of second primary cancers in laryngeal cancer patients treated with radiotherapy
PO-1201
Abstract
Prognostic impact of second primary cancers in laryngeal cancer patients treated with radiotherapy
Authors: Chiyoko Makita1, Takayuki Mori1, Hirota Takano1, Tomoyasu Kumano1, Masayuki Matsuo1
1Gifu University, Radiology, Gifu, Japan
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Purpose or Objective
Second primary cancers (SPCs) develop in 3.8-20.5% of patients with laryngeal cancer. The aim of this study is to investigate the impact of SPCs in patient treated with radiotherapy for laryngeal cancer.
Material and Methods
We retrospective reviewed laryngeal cancer patients who underwent radical radiotherapy from January 2007 to December 2018. Median age was 70 years old (range, 40-88), male/female=107/4, supraglottic/glottic/subglottic=8/101/2, T: 1a/1b/2/3=45/14/44/8, N: 0/1/2b/2c=101/8/1/1, 47 patients (41.8%) were treated with concurrent chemotherapy. Fifty-eight patients were treated with conventional 66-70 Gy (daily 2 Gy/fraction), and 53 patients were treated with hypofractionated 56.25-67.5 Gy (daily 2.25 Gy/fraction). According to the timing of diagnosis for each constituent tumor, SPCs are classified into 2 categories: synchronous SPCs if constituent tumors emerge simultaneously or within 2 months or metachronous SPCs otherwise.
Results
The median follow-up period was 66 months (5-122 months), the 5-year survival rate was 82.3%, the progression-free survival rate was 84.8%, the local control rate was 81.8%, and the larynx preservation rate was 91.9%. Recurrence was seen in 18 cases, and the recurrence type was local in 16 cases and cervical lymph node in 2 cases. Death from the primary disease occurred in 4 cases, while death from other diseases was observed in 20 cases (SPC in 12 cases, pneumonia in 3 cases, ALS in 1 case, accidental death in 1 case, heart failure in 1 case, and unknown in 2 cases). Synchronous SPCs were observed in 22 cases (20%), and the cumulative incidence of metachronous SPCs was 22.5% at 5 years. On multivariate analysis, age, PS, T-stage, and presence of synchronous and metachronous SPCs were significant prognostic factors for overall survival (HR, 0.28; 95% CI, 0.11-0.95; P=.05). Gastric cancer (11 cases) was the most common SPC, followed by lung cancer (9 cases) and esophageal cancer (5 cases).
Conclusion
SPCs were considered to be an important prognostic factor. Future attempts to improve laryngeal cancer survival need to target SPCs.