Combination Chemotherapy Using Cyclophosphamide and High Dose Dexamethasone with or without Radiotherapy for the Treatment of Multiple Myeloma.

Forty two people (men 22, women 20) diagnosed as Durie-Salmon stage IIIA or B multiple myeloma were treated with a combination chemotherapy consisting of cyclophosphamide at 400mg and dexamethasone at 40mg (CHD) regardless of body surface for 4 or 5 consecutive days every 3 or 4 weeks from August 1996 through July 2005. The treatment was repeated as long as the patient could tolerate or until disease progressed. The chemotherapy was given to 36 chemo-naïve patients as primary therapy and to 6 patients exposed to VAD (vincristine, doxorubicin, dexamethasone) as salvage therapy. Palliative loco-regional radiotherapy was also given to 20 of 44 patients. A total of 433 cycles (mean 10.3, range 2~28 per individual) of chemotherapy were given and the response evaluation was made in accordance to the criteria of Dr. Blade. SD (stable disease) was defined as reduction or increase of myeloma protein within 25%. Six of 36 chemo-naïve patients who did not respond to CHD received salvage therapy consisting of VAD or MP (melphalan plus prednisone). Eleven patients (26%) attained CR (complete remission) at a median of 7 cycles (range 4~10), 15 (36%) achieved PR (partial remission) at a median of 3 cycles (range 2~16), 12 (28%) stayed at SD, and 4 patients (10%) showed PD (progressive disease). The measurement of survival duration was started at the beginning of the CHD chemotherapy. The measurement was censored in 6 patients at the time of stem cell transplant, 5 autologous (one was disease free at 108 months after transplant), and 1 allogeneic. On a mean follow-up period of 15.1 months (range 3~59), 15 people remained alive at 3, 3, 3, 4, 6, 6, 8, 10, 14, 15, 16, 16, 16, 26, and 37 months. The mean response duration and OS (overall survival) of the patients who entered CR were 7 (range 2~18) and 31.3 (range 6+~59) months respectively. The correspondent durations of the patients in PR were 7.9 (range 2+~28) and 15 (range 3+~37+). The corresponding durations of the patients in SD were 8.3 (range 2~26) and 13.5 (3+~48). The mean OS duration of the patients in PD was 5.3 (range 3~8). The difference in OS durations between patients in PR and those in SD was not statistically meaningful. Five of 6 patients exposed to VAD responded to CHD, whereas one of 5 patients exposed to CHD did to VAD. Two of 4 patient exposed to CHD responded to MP. Adverse effect was minimal with non-fatal events including 5 febrile episodes of unknown origin, 3 cases of pneumonia, 2 cases of urinary tract infection, 1 case of peritonitis, 1 case of herpes zoster, and 1 case of intractable nausea during the 433 chemotherapy courses. There were 2 cases of fatal septicemia and 1 case of fatal pneumonia during the period. CHD combination chemotherapy seems an active and less toxic regimen in the treatment of multiple myeloma.