Predicting outcome in mantle cell lymphoma

This study developed a method of predicting prognosis for patients with advanced mantle cell lymphoma (MCL). The authors concluded that the MCL International Prognostic Index (MIPI) was more accurate for MCL compared to those developed for other types of lymphoma.

Mantle cell lymphoma (MCL) is an uncommon form of non-Hodgkin lymphoma. Outcomes in MCL have been relatively poor. Methods of determining appropriate treatments are therefore needed.

The International Prognostic Index (IPI) is an accepted method of predicting outcome in patients with other forms of lymphoma. A separate version has been developed for patients with follicular lymphoma (the FLIPI). Previous studies have found that the IPI and FLIPI are not necessarily accurate predication tools for MCL.

The current study examined the development of a new prognosis prediction method for MCL. Data from three previous trials, including 455 patients, were included. All patients had advanced stage disease and were treated with some form of chemotherapy. 80% of 438 patients achieved a partial or complete remission (decreased or no signs of cancer activity). 18% achieved complete remission. Average follow-up was 32 months.

Based on the IPI, 23% of patients were determined to be low-risk. 40% were low-intermediate risk. 28% were high-intermediate risk. 9% were high risk. Roughly two thirds of patients were included in the low and high intermediate risk groups, and were not well separated.

Based on the FLIPI, 6% of patients were considered low risk, 30% were intermediate risk, and 64% were high risk. The average 5-year overall survival for low risk patients was 61% and 57% for intermediate risk. The average overall survival for high risk patients was 48 months. These survival rates are not clearly defined by risk group.

Of the characteristics that were taken into account by the IPI and FLIPI, only some were found to be predictive of survival in MCL. These were age, performance status (ability of the patient to function), lactate dehydrogenase levels (LDH, an indication of cell or tissue damage), and number of white blood cells.

The MIPI was tested on 409 patients. 44% were considered low risk, 35% were considered intermediate risk, and 21% were considered high risk. Overall survival was 51 months for intermediate risk patients and 29 months for high risk patients.

Ki-67 is a protein in the blood associated with cancer cell growth. Increased Ki-67 levels were predictive of overall survival.

The authors concluded that the MIPI provided a clear separation of three risk groups with very different prognoses.