Intraperitoneal chemotherapy showed benefit in gastric cancer

The two-drug regimen of docetaxel and cisplatin, however, was not superior to 5-FU/leucovorin/cisplatin.

CHICAGO — Postoperative chemotherapy with intraperitoneal cisplatin appeared to improve recurrence-free survival and overall survival in patients with grossly serosa-positive advanced gastric cancer.

Data from this study were presented at the 2008 ASCO Annual Meeting by Yoon-Koo Kang, MD, PhD, a professor of oncology at Asan Medical Center in Seoul.

Kang and colleagues randomly assigned 640 patients who had D2 resection to two postoperative treatment arms. In arm A, the patients received mitomycin-C three to six weeks after surgery and doxifluridine, a 5-FU prodrug, for three months.

In arm B, patients received intraperitoneal cisplatin during surgery, mitomycin-C one day after surgery, doxifluridine for 12 months and six additional cycles of cisplatin. After a median follow-up of 3.5 years, patients in arm B had a better relapse-free survival (HR=0.70) and a better overall survival (HR=0.71) compared with patients in arm A.

Although the trial was well powered and well designed, it is not enough to make a definite conclusion as to the benefit of intraperitoneal cisplatin, according to David Ilson, MD, PhD.

“There were four different variables involved in this trial,” Ilson, an associate attending physician at Memorial Sloan-Kettering Cancer Center and a member of the HemOnc Today Editorial Board, told HemOnc Today. “Although the data suggest there is a benefit for intraperitoneal cisplatin, the bottom line is that we need a confirmatory phase-3 trial in which that is the only variable.”

Metastatic gastric cancer

Other study data presented at the meeting demonstrated no benefit of docetaxel plus cisplatin compared with 5-FU and cisplatin for metastatic gastric cancer. These data were presented by Karsten Ridwelski, MD, PhD, of the division of oncology at City Hospital Magdeburg in Germany.

According to Ilson, data from recent studies in the United States and Europe showed that adding docetaxel to cisplatin and 5-FU resulted in a higher response rate and a modest improvement in overall survival.

“Docetaxel is now being recommended for first-line chemotherapy, but the problem is that the three-drug regimen is very toxic,” Ilson said. “The researchers here looked at a two-drug regimen given once every three weeks, modeled after a treatment schedule for colon cancer.”

Ridwelski and colleagues randomly assigned 273 patients to receive docetaxel/cisplatin or 5-FU/leucovorin/cisplatin. At 12 months follow-up, the overall response rates were 29.5% for docetaxel/cisplatin and 29.3% for 5-FU/leucovorin/cisplatin. There was also no difference in median time to progression or median overall survival.

These data are in contrast to the three-drug regimen, which was superior to cisplatin/5-FU, Ilson said. The three-drug regimen, however, is limited by toxicity.

“If using the three-drug regimen, it is better to use lower starting doses and model the treatment schedule after a colon cancer treatment schedule, both of which seem to lower toxicity,” Ilson said. “For most patients, however, it’s probably better to give two-drug chemotherapy.” – by Emily Shafer

For more information:
Kang Y, Chang H, Zang D, et al. #LBA4511.
Ridwelski K, Fahlke J, Kettner E, et al. #4512.
Both presented at: 2008 ASCO Annual Meeting; May 30-June 3, 2008; Chicago.