TKIs induce complete remission in metastatic RCC patients
MedWire News: Tyrosine kinase inhibitors (TKIs) can induce complete remission (CR), either alone or in combination with local treatment, in patients with metastatic renal cell carcinoma (mRCC), study data show.
"Furthermore, stopping treatment with a TKI after CR may be an acceptable option," report Laurence Albiges (Institut Gustave Roussy, Villejuif, France) and colleagues in the Journal of Clinical Oncology.
"The characteristics of patients achieving CR during treatment with a TKI are not well defined. Furthermore, it is not yet clear if patients achieving CR should continue targeted therapy or if it is feasible for them to discontinue treatment," say the researchers.
To investigate, Albiges and team retrospectively reviewed the medical records of 64 mRCC patients who achieved CR during treatment with the TKIs sunitinib or sorafenib, with or without additional local treatment, at 15 centers across France and Switzerland between 2005 and 2009.
The majority (95%) of patients were classified as favorable or intermediate risk; however, three patients at poor prognostic risk also achieved CR.
There were 36 patients that received TKI treatment alone and 28 that received a TKI plus local treatment, namelysurgery, radiotherapy, or radiofrequency ablation.
Although the total number of patients treated with sunitinib or sorafenib was not available for all centers, the incidence of CR within the main center was 1.7% (six of 353 patients treated during the enrolment period.)
During a median follow-up period of 13 months from CR, 53 patients discontinued TKI therapy, whereas 11 continued to receive treatment. A total of 29 (55%) patients who discontinued treatment remained in CR after a median follow-up period of 8.5 months.
Among the patients who achieved CR with TKI alone, 28 stopped TKI treatment after CR, whereas eight continued with their treatment. After median follow-up periods of 8.5 and 10.3 months, respectively, 61% of patients who stopped treatmentand 87% of those who continued treatment were still in CR.
Twenty-five of the 28 patients in CR after TKI plus local treatment did not continue with treatment after CR, while the remaining three did. Of the patients who stopped treatment, 48% remained in CR after 10.7 months of follow-up, compared with 66% among those who continued therapy for a median follow-period of 8.2 months.
The researchers note that they could not identify any clinical or biologic parameters that were associated with a patient being more or less likely to achieve CR.
Furthermore, "because of the small number of patients in each group, it was not possible to draw any conclusions about differences in relapse rates between patients who continued or stopped therapy."
Albiges and co-authors conclude that further research is needed "to identify factors to aid selection of patients who would be at less risk of recurrence after discontinuation of treatment."
By Laura Cowen