Treatment Strategy and Prognosis of Myeloma Patients According to ISS Stage at Diagnosis.

Background: Recently, a new ISS staging system for myeloma has been developed. By analyzing over 10,000 patients, ISS is a simple and useful system to estimate prognosis. However, by ISS, survival time was evaluated only for the time after chemotherapy. The prognosis of untreated patients and survival time after initial diagnosis were not well understood by ISS. Our aim was to evaluate the prognosis and define treatment strategy for newly diagnosed, untreated myeloma patients using ISS at diagnosis. Especially, treatment strategy for ISS stage I was received attention.

Methods: 127 newly diagnosed, untreated myeloma patients referred to Nihon University Itabashi Hospital between 1994 and 2004 were retrospectively analyzed. ISS stage was determined with the laboratory data at diagnosis. Median age of the patients was 62 y (range 30–88). Median follow-up duration was 32.5 months (range 0–171). Transplanted patients were censored at the time of transplantation.

Results: 50% survival duration after initial diagnosis for stage I (n=54), II (n=26), and III (n=47) were 106, 36, and 14.5 months, respectively. For stage I patients given chemotherapy, both 50% survival times after initial diagnosis and after chemotherapy were the same, 85 months, suggesting that stage I patients required chemotherapy were treated early after diagnosis. Fifteen stage I patients have not been treated and all of them are alive. Of these 15 patients, 14 were in Durie-Salmon stage I and one was in Durie-Salmon stage II at diagnosis. 50% progression time from ISS stage I to II in untreated patients was 2 months. For the patients treated at ISS stage I, 50% progression time from stage I to II and I to III were 61 and 155 months, respectively. These data suggest that the progression from stage I to II could be postponed by early chemotherapy. However, overall survival duration of the patients treated at stage I and of those treated after progression to stage II was not different.

Conclusion: We defined treatment strategy for myeloma using ISS at diagnosis. Certain amounts of myeloma patients with Durie-Salmon stage I and ISS stage I concomitantly at diagnosis were not required chemotherapy. Administration of chemotherapy for ISS stage I patients at diagnosis are recommended after they progress to stage II.