IASLC: Mesothelioma Subtype Has Lengthier Projected Longevity

SEOUL -- Some patients with malignant mesothelioma may have a prognosis that's not quite so grim as widely believed, a Nordic collaborative group reported here.

SEOUL, Sept. 4 -- Some patients with malignant mesothelioma may have a prognosis that's not quite so grim as widely believed, a Nordic collaborative group said here.

Patients with epithelial subtype mesothelioma treated with chemotherapy alone had a median survival of 15 months, and some patients survived beyond three years, Gunnar Hillerdal, M.D., of the Karolinska University Hospital in Stockholm, and colleagues, reported at the International Association for the Study of Lung Cancer meeting.

The experience of the Nordic group contrasts with the clinical perception that mesothelioma patients die within a year, the investigators noted. A large U.S.-based multicenter trial of cisplatin with or without pemetrexed demonstrated a survival of 12 months versus nine months with cisplatin alone. Other trials have yielded similar results.

"The experience of the Nordic Mesothelioma Group is different," said Dr. Hillerdal.

In the Nordic countries, surgery is used sparingly in the treatment of mesothelioma. Elsewhere in the world, patients with the most favorable characteristics (such as good performance status and lower-stage disease) often are indicated for surgery, leaving patients with the worst prognosis for treatment with chemotherapy, said Dr. Hillerdal.

Nordic investigators analyzed data on 147 mesothelioma patients treated with chemotherapy alone and followed until death or for a minimum of 18 months. All the patients were given liposomal doxorubicin, carboplatin, and gemcitabine.

Analysis of survival by histologic subtype showed that epithelial subtype accounted for 108 patients (73%), mixed subtype for 21 patients (14%), and sarcomatous subtype for 18 patients (12%).

Among patients with epithelial subtype mesothelioma, 44% survived at least 18 months, 25% survived for two years, 9% lived three years or longer, and two patients remained alive after five years of follow-up. Patients with epithelial stage IV disease (distant metastases) had a median survival of 11 months, two lived for at least two years, and one patient remained alive at 61 months.

"This is actually better than stage IV non-small-cell lung cancer," Dr. Hillerdal commented.

Patients with mixed subtype or sarcomatous disease had a less favorable outlook, reflected in a median survival of eight months and four months, respectively. No patient in either group survived as long as two years.

"The key message from this study is that survival of mesothelioma is not so bad as many people believe," said Dr. Hillerdal. "With proper patient selection survival with chemotherapy can be just as good as with surgery or even better. The important thing to remember is patient selection. Subtype is more important than stage, and that should be kept in mind when evaluating results of surgical series."