Active surveillance of renal cortical neoplasms: a contemporary review

Differences in Renal Tumor Size Measurements for Computed Tomography Versus Magnetic Resonance Imaging: Implications for Patients on Active Surveillance

PURPOSE

To evaluate and compare the accuracy of computed tomography (CT) and magnetic resonance imaging (MRI) in predicting the final pathologic tumor size of partial nephrectomy specimens.

MATERIALS AND METHODS

We analyzed a multi-institutional database of 807 patients who underwent robotic partial nephrectomy for a cT1a renal mass from 2006 to 2016. Patients who had a solitary tumor with complete data on the baseline imaging modality and the tumor size (baseline and pathologic) (n = 349) were included for analysis. Baseline tumor size evaluated by both imaging modalities, in addition to the difference between the measurements and final pathologic tumor size (cm) measurements, was compared between patients who received a baseline CT (n = 276, 79.1%) and those who received an MRI (n = 73, 20.9%).

RESULTS

There were no statistically significant differences between any baseline characteristics and receipt of a CT versus MRI. In multivariable analysis adjusting for confounders, there was no significant difference in the baseline tumor size between patients receiving an MRI and those receiving a CT (2.3 versus 2.6 cm; β = -0.13; 95% confidence interval [CI] = -0.33 to 0.07; P = .208). Tumor size on imaging was smaller from final pathology by 0.43 cm on average (P = .002). Measurement error for the measured baseline versus actual pathologic tumor size did not significantly differ for patients receiving an MRI versus those receiving a CT (0.38 versus 0.44 cm; β = -0.06; 95% CI = -0.16 to 0.04; P = .232).

CONCLUSION

Baseline renal tumor size measurements were not significantly different for CT scan and MRI. Choice of imaging modality can be based on doctor and patient preference, including cost and exposure to radiation.

[Focal therapy and prostate cancer]

The International Task Force on Prostate Cancer defines focal therapy (FT) for prostate cancer (PCa) as the therapy that "selectively ablates known disease and preserves existing functions, with the overall objective of minimizing lifetime morbidity without compromising life expectancy". FT for the treatment of PCa has been called the "male lumpectomy", an analogue to women's breast lumpectomy for the treatment of breast cancer. Radical prostatectomy continues to be the most frequently performed treatment for localized PCa, as anatomic knowledge and several technical advances, i.e. the introduction of robotic assisted surgery, have led to successful oncological outcome and lower rates of post-treatment morbidity. However, a proportion of patients still experiences a no negligible sexual, urinary, and bowel morbidity. Although the rationale of active surveillance for low-risk PCa (PSA <10 ng/mL, Gleason grade 6 or less, and clinical stage T1c-T2a) is sound, only few of newly diagnosed patients elect this approach. Thus, in the recent years the concept of a "subtotal therapy" gained the interest of some urological schools. The aim of this paper is to review the existing literature in order to provide the status of art on FT for PCa. The manuscript will focus on the characteristics of the target population, on the pre-operative evaluation to localise disease, as well as on perioperative, functional, and disease-control following focal therapy.

The role of focal therapy in the management of localised prostate cancer: a systematic review

CONTEXT

The incidence of localised prostate cancer is increasing worldwide. In light of recent evidence, current, radical, whole-gland treatments for organ-confined disease have being questioned with respect to their side effects, cancer control, and cost. Focal therapy may be an effective alternative strategy.

OBJECTIVE

To systematically review the existing literature on baseline characteristics of the target population; preoperative evaluation to localise disease; and perioperative, functional, and disease control outcomes following focal therapy.

EVIDENCE ACQUISITION

Medline (through PubMed), Embase, Web of Science, and Cochrane Review databases were searched from inception to 31 October 2012. In addition, registered but not yet published trials were retrieved. Studies evaluating tissue-preserving therapies in men with biopsy-proven prostate cancer in the primary or salvage setting were included.

EVIDENCE SYNTHESIS

A total of 2350 cases were treated to date across 30 studies. Most studies were retrospective with variable standards of reporting, although there was an increasing number of prospective registered trials. Focal therapy was mainly delivered to men with low and intermediate disease, although some high-risk cases were treated that had known, unilateral, significant cancer. In most of the cases, biopsy findings were correlated to specific preoperative imaging, such as multiparametric magnetic resonance imaging or Doppler ultrasound to determine eligibility. Follow-up varied between 0 and 11.1 yr. In treatment-naïve prostates, pad-free continence ranged from 95% to 100%, erectile function ranged from 54% to 100%, and absence of clinically significant cancer ranged from 83% to 100%. In focal salvage cases for radiotherapy failure, the same outcomes were achieved in 87.2-100%, 29-40%, and 92% of cases, respectively. Biochemical disease-free survival was reported using a number of definitions that were not validated in the focal-therapy setting.

CONCLUSIONS

Our systematic review highlights that, when focal therapy is delivered with intention to treat, the perioperative, functional, and disease control outcomes are encouraging within a short- to medium-term follow-up. Focal therapy is a strategy by which the overtreatment burden of the current prostate cancer pathway could be reduced, but robust comparative effectiveness studies are now required.

Growth kinetics and active surveillance for small renal masses

PURPOSE OF REVIEW

Management options for small renal masses (SRMs) include excision, ablation, and active surveillance. Increasing interest in active surveillance, particularly for tumors of limited oncologic potential, in patients with other significant health concerns continues to rise, but precise protocols are still lacking.

RECENT FINDINGS

A review of 18 retrospective series of patients undergoing active surveillance for 957 SRMs indicates that the majority grew during observation (mean 0.32  cm/year), but only 1.4% metastasized during 32 months of follow-up (median). One published prospective series of 209 SRMs reported average growth of 0.13  cm/year and only 1% metastasized. Maximal tumor diameter (or volume) at presentation is a predictor of growth rate, high-grade disease, and likelihood of metastasis. SRMs less than 3  cm are very unlikely to metastasize and deferring treatment has not been associated with increased failure to cure.

SUMMARY

Active surveillance is a reasonable initial strategy in most patients with SRMs, particularly those with limited life-expectancy and increased perioperative risk. Intervention should be considered for growth to greater than 3-4  cm or by greater than 0.4-0.5  cm/year while on active surveillance.