Research article

The incidence and risk of developing a second primary esophageal cancer in patients with oral and pharyngeal carcinoma: a population-based study in Taiwan over a 25 year period

Kuan-Der Lee^1,2,3†, Chang-Hsien Lu^1,2,3†, Ping-Tsung Chen^1,2,3, Chunghuang H Chan^1,2,3, Jen-Tsun Lin^1,2,3, Cih-En Huang¹, Chih-Cheng Chen^1,2,3 and Min-Chi Chen^4*

• * Corresponding author: Min-Chi Chen mcc@mail.cgu.edu.tw

• † Equal contributors

Author Affiliations

¹ Department of Hematology and Oncology, Chang Gung Memorial Hospital at Chiayi, Taiwan, Republic of China

² Department of Medicine and Graduate Institute of Clinical Medical Sciences, Chang Gung University, Tao-Yuan

³ Chang Gung Institute of Technology, Chia-yi Campus, Chiayi, Taiwan, Republic of China

⁴ Department of Public Health and Biostatistics Consulting Center, School of Medicine, Chang Gung University, Tao-Yuan, Taiwan, Republic of China

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BMC Cancer 2009, 9:373 doi:10.1186/1471-2407-9-373

Published: 20 October 2009

Abstract

Background

The incidence of oral and pharyngeal (including oral cavity, oropharynx and hypopharynx) carcinoma increases rapidly in Asia and South Pacific because of betel quid chewing. Thus far, large-scale epidemiological studies are not available yet to stratify these patients by their risks of developing a second primary cancer in the digestive tract including esophagus, stomach, colon, and rectum.

Methods

A population-based study was conducted using the database from the Taiwan National Cancer Registry for the period 1979-2003. We quantified standardized incidence ratios (SIRs) and cumulative incidence of second primary cancers among 33,787 patients with initial diagnoses of oral and pharyngeal carcinoma.

Results

Among these four digestive tract organs, the esophagus was the only site of second cancer with excess risk in patients with oral and pharyngeal carcinoma. The incidence and risk of developing a second primary esophageal cancer differed by the site of the primary index tumor, most frequently seen in hypopharyngeal cancer (71/4,218 = 1.68%, SIR = 22.76, 95% CI 17.77-28.70), followed by oropharyngeal cancer (30/3,403 = 0.88%, SIR = 14.29, 95% CI 9.64-20.39) and the least in oral cavity cancer (99/26,166 = 0.38%, SIR = 5.57, 95% CI 4.53-6.78). In addition, the risk was extraordinarily high for patients with a follow-up interval ≤ 1 year and those with first primary cancer diagnosed at age ≤50. These patients may justify more close surveillance.

Conclusion

The present study represents the first population-based study in Asia attempting to stratify the patients of oral and pharyngeal carcinoma by their risk of developing a second esophageal cancer. It helps identify patients at high risk and tailor the application of intense follow-up surveillance to the estimated risk in each individual case.