Process and preliminary outcome of a patterns-of-care study of esophageal cancer in Japan: patients treated with surgery and radiotherapy.
OBJECTIVE
To evaluate the quality of radiotherapy (RT) in Japan, we have been carrying out a national survey through patterns-of-care studies (PCSs) since 1996. We present the preliminary results of surgery combined with RT with or without chemotherapy for thoracic esophageal cancer.


METHODS
A Japanese PCS data format for esophageal cancer was established based on one used in the United States and including information used in the surgical registration system in Japan, so that the results in both countries could be compared. An independent panel of radiation oncologists surveyed randomly selected institutions and patients between September 1998 and March 2001. There were 767 esophageal cancer patients, of whom 220 had undergone preoperative or postoperative RT.


RESULTS
The median age of the 220 patients was 62.3 years (range 31-89); of them, 88.1% were men. Pathologically, 218 patients (99.5%) had squamous cell carcinoma, predominantly located in the middle and lower thoracic esophagus, 41.7% of the patients had Stage III disease; they accounted for 52.6% of patients in nonacademic institutions and for 37.7% of those in academic institutions (p = 0.016). Sixty-nine patients received preoperative RT; of them, 60.9% received chemotherapy; 145 patients received postoperative RT with or without chemotherapy. The spinal cord of 23 (11.7%) of 196 patients was irradiated with >/=50 Gy. In academic institutions, extended radical "three-field" lymphatic dissection was performed for 72 (48.7%) of 148 patients; however, this sophisticated surgical procedure was done in only 13 (25.5%) of 51 patients in nonacademic settings (p = 0.004). In all large academic institutions (those treating >/=300 patients annually), >/=6 MV of photon energy was used; 30.5% of nonacademic institutes had linear accelerators of <6 MV photon (p = 0.001). No deviations occurred in the radiation dose (median 46 Gy), fractionations, or fields between the two types of institutions. Univariate analyses showed that the statistically significant prognostic factors affecting overall survival were stage (p = 0.001), extended radical "three-field" lymphatic dissection (p = 0.001), no residual tumor (p = 0.001), supraclavicular RT (p = 0.001), mediastinal RT (p = 0.025), Karnofsky performance status (p = 0.006) photon energy (p = 0.011), and stratification of the institutions (p = 0.001). Multivariate analysis showed that the type of institution (p = 0.045, risk ratio = 0.604), stage (p 0.029, risk ratio = 0.572), no residual tumor (p = 0.006, risk ratio = 0.487), photon energy (p = 0.043, risk ratio = 0.579), and use of chemotherapy (p = 0.012, risk ratio = 1.907) significantly affected overall survival.


CONCLUSIONS
This PCS showed that in Japan important issues are present regarding RT for esophageal cancer that should be solved immediately, namely, treatment strategy, photon energy, and dose applied to the spinal cord. The PCS provided important information on how much improvement in structure and process would be required nationwide for RT of esophageal cancer.
Gomi
Kotaro
K
Department of Radiation Oncology, Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan. kgomi@jfcr.or.jp
Oguchi
Masahiko
M
Hirokawa
Yutaka
Y
Kenjo
Masahiro
M
Ogata
Toshiyuki
T
Takahashi
Yutaka
Y
Nakamura
Naoki
N
Yamashita
Takashi
T
Teshima
Teruki
T
Inoue
Toshihiko
T
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery*; D003131:Combined Modality Therapy; D004938:Esophageal Neoplasms / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery*; D005260:Female; D006801:Humans; D007564:Japan; D017567:Karnofsky Performance Status; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011879:Radiotherapy Dosage; D014481:United States