The promise of an active surveillance strategy in patients with metastatic renal cancer

Cristina Suárez, Physician-Scientist, VHIO´s Genitourinary, CNS Tumors, Sarcoma & Cancer of Unknown Primary Site Group, headed by Joan Carles, and Medical Oncologist at the Vall d´Hebron University Hospital (HUVH), has participated in a prospective, phase II clinical trial with metastatic renal-cell carcinoma patients, in collaboration with investigators from North American and the UK. The study*, published ahead of print in last month´s The Lancet Oncology, was led by renowned expert Brian Rini from the Cleveland Clinic Taussig Cancer Institute, Ohio, USA. Results showed that this subset of patients may benefit from delaying the initiation of systemic therapy through a tailored and optimal active surveillance plan, facilitating an approximation of when best to start anti-cancer treatment in each individual case.

Anti-angiogenic therapies represent the cornerstone of therapy for metastatic renal-cell carcinoma. Once initiated, as long as the disease remains under control, they are indefinite in duration. Although these medicines are considered standard of care, they are not curative. The decision to proceed with therapy must therefore be weighed against the overall burden of treatment including considerations such as toxicity and cost.

The clinical study, enrolling 48 patients with metastatic renal-cell carcinoma, evidenced a subgroup of patients who, upon kidney removal, can benefit from active surveillance as an initial strategy for over a year prior to starting systemic therapy, and, without risking their health.

One of the most novel aspects of this study is the ability to predict how a subgroup of patients with indolent yet metastatic disease, can benefit from a period of active surveillance prior to initiation of treatment. The authors link a long period of active surveillance with patients with limited sites of metastatic disease and few risk factors as outlined by the International Metastatic Database Consortium (IMDC). “According to this criterion, the group of patients with a low-risk index score could successfully remain under surveillance for practically 3 times longer than patients with a high-risk index score, with mean values 22.2 versus 8.4 months,” says Cristina Suárez.

Active surveillance terminated either when the physician and his/her respective patient took the joint decision to start the administration of a pharmacological treatment or if the patient withdrew consent.

This approach may be advantageous over systemic therapy since patients undergoing active surveillance are less immunocompromised and therefore have a greater capacity to attack cancer cells. Thus, active surveillance as a therapeutic approach in selected patients, according to the indications that Rini and co-collaborators highlight in their study, could help delay toxicity associated with targeted therapies, reduce treatment time as well as the economic burden placed on healthcare systems.

###

*Rini BI,Dorff TB, Elson P, Suarez C, Shepard D, Wood L, Humbert J, Pyle L, Wong YN, Finke JH, Rayman PA, Larkin JM, Garcia JA, Plimack ER. Active surveillance in metastatic renal-cell carcinoma: a prospective, phase 2 trial. Lancet Oncol. 2016 Aug 3. doi: 10.1016/S1470-2045(16)30196-6.