According to research recently presented at the American Urological Association annual meeting, clinicians may have an improved ability to predict treatment outcomes in patients with renal cell carcinoma (RCC).
The studies presented either build on or confirm previous research or identify novel prognostic markers, which include tumor shrinkage, preoperative C-reactive protein levels, or preoperative nutritional screening.
Takafumi Yagisawa, MD, and colleagues at Tokyo Women’s Medical University, presented the findings of a study looking at the outcomes of 199 patients with metastatic RCC (mRCC) who recieved first-line systemic therapy with sunitinib (71 patients), sorafenib (47 patients), pazopanib (4 patients), or temsirolimus (7 patients).1
The study showed that the 81 patients who had maximum tumor shrinkage within 3 months—as measured by computed tomography (CT)—had significantly longer overall survival than the 48 patients who had maximum shrinkage after 3 months (22.8 vs. 14.3 months, respectively).1
In another study, investigators led by Hideaki Miyake, MD, of Kobe University Graduate School of Medicine in Japan, examined tumor shrinkage as a predictor of overall survival among 185 patients with mRCC who received first-line therapy with sunitinib (120 patients) or sorafenib (65 patients) for 3 or more months.2
Three patients had a complete response to therapy and 40 had a partial response. Another 105 patients showed stable disease, while 37 experienced disease progression. The median progression-free survival was 7.3 months, and overall survival was 33.6 months.2
After 3 months on the medications, 9 patients experienced tumor shrinkage of 50% to 100%; 43 patients had tumor shrinkage ranging from 25% to 49%; and 61 patients had 0% to 24% tumor shrinkage. The remaining 72 patients had tumor enlargement or new metastatic lesions.
Overall survival rates by level of tumor shrinkage (from greatest to least) were 59 months, 39 months, 31 months, and 16 months, respectively.2
In multivariate analysis, Memorial Sloan Kettering Cancer Center classification, C-reactive protein level, liver metastasis, and early tumor shrinkage were significantly and independently associated with overall survival.2
“Considering the potential impact of early tumor shrinkage on the subsequent prognosis of patients with mRCC, it is very important to select first-line agents with an ability to induce prompt tumor remission in order to achieve a favorable prognosis,” Dr. Miyake said.
Meanwhile, Viktor Gruenwald, MD, and colleagues presented findings at the 2015 American Society of Clinical Oncology annual meeting in Chicago, IL, that reported on a study of 4,736 patients with mRCC.
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Their research demonstrated that RCC early tumor shrinkage of 7% or 8% provides the optimal cut-off for predicting progression-free and overall survival, and that the conventional 30% tumor shrinkage threshold is too high.3
The researchers used data from Pfizer-sponsored clinical trials with sorafinib, axitinib, sunitinib, interferon-alfa, and temsirolimus.
The researchers evaluated early tumor shrinkage at the first post-baseline scan. They classified patients as responders if progression-free and overall survival times (7 months and 20 months, respectively) were above the median.3