A PET/CT scan at 6 months post-induction adds prognostic value for patients with newly diagnosed multiple myeloma (NDMM), according to researchers.
A negative PET/CT scan at 6 months was linked to prolonged time to next treatment (TTNT) and overall survival (OS) in a retrospective study. The findings were published in Blood Advances.
The study included 195 patients with NDMM who underwent PET/CT at diagnosis and approximately 6 months after study entry. The median age was 61 years at diagnosis.
The most common induction regimens patients received were lenalidomide plus bortezomib and dexamethasone (28.7%), cyclophosphamide plus bortezomib and dexamethasone (22.5%), and lenalidomide plus dexamethasone (22.2%).
For the entire cohort, the median follow-up was 80.6 months, the median TTNT was 24.6 months, and the median OS was 79 months. At 6 months, 25.6% of patients had a negative PET/CT scan, 74.6% had detectable disease, and 15.3% had signs of progression.
The median TTNT was significantly longer in patients with a negative PET/CT scan than in those with a positive PET/CT scan — 55.2 months and 17.8 months, respectively (P <.0001).
The median OS was significantly longer in patients with a negative PET/CT scan as well. It was not reached for patients with a negative scan and was 60.8 months for those with a positive scan (P <.0001).
TTNT was numerically, but not significantly, longer in patients who had a complete response (CR) and negative PET/CT scan than in those who had a hematologic response only — 58.9 months and 39.2 months, respectively (P =.27).
OS was significantly longer in patients who had a CR and negative PET/CT. The median OS was not reached for patients with a CR and negative PET/CT and was 72 months for those with a hematologic response only (P =.001).
The prognostic significance of PET/CT for TTNT and OS was retained in a multivariate analysis. Patients with a positive PET/CT at 6 months had a hazard ratio of 1.7 (95% CI, 1.02-2.9) for TTNT and 3.26 (95% CI, 1.35-7.9) for OS.
“[A negative PET/CT] at 6 months confers a significant prognostic advantage for newly diagnosed MM patients and adds significant value to the hematologic response assessment,” the researchers concluded.
They added that “PET/CT could be incorporated in the post-treatment evaluation of patients with NDMM, as it adds crucial prognostic information in the biochemical assessment.”
Charalampous C, Goel U, Broski S, et al. Utility of PET/CT in assessing early treatment response in patients with newly diagnosed multiple myeloma. Blood Adv. Published online March 2, 2022. doi:10.1182/bloodadvances.2022007052