[Histopathologic grading of breast cancer; large variation with major consequences?] / Histopathologische gradering van het mammacarcinoom.

The pathologist's assessment of tumor tissue plays a critical role in therapeutic decision-making in early-stage invasive breast cancer. In daily practice, however, there appears to be considerable variation in grading between the different Dutch pathology laboratories and between individual pathologists within the same laboratory. This underlines the need to standardize grading by pathologists as much as possible in order to minimize the risk of a worse outcome for patients due to under-treatment and of unnecessary toxicity from over-treatment. Therefore, two initiatives were launched, i.e. laboratory-specific feedback reports and an e-learning module in which pathologists were trained in grading of invasive breast cancer. While these initiatives have yielded encouraging results, the overall variation in grading remains significant. Awareness of this variation, and of the inherent difficulties of subjective grading, among the various clinicians involved in breast cancer management, is therefore of utmost importance to improve clinical decision-making for patients.

The increasing importance of histologic grading in tailoring adjuvant systemic therapy in 30,843 breast cancer patients.

PURPOSE: The large variation in histologic grading of invasive breast cancer (IBC) that has been reported likely influences tailoring adjuvant therapy. The role of grading in therapeutic decision-making in daily practice, was evaluated using the Dutch national guidelines for IBC-management. METHODS: Synoptic reports of IBC resection-specimens, obtained between 2013 and 2016, were extracted from the nationwide Dutch Pathology Registry, and linked to treatment-data from the Netherlands Cancer Registry. The relevance of grading for adjuvant chemotherapy (aCT) was quantified by identifying patients for whom grade was the determinative factor. In addition, the relation between grade and aCT-administration was evaluated by multivariate logistic regression for patients with a guideline-aCT-indication. RESULTS: 30,843 patients were included. Applying the guideline that was valid between 2013 and 2016, grade was the determinative factor for the aCT-indication in 7744 (25.1%) patients, a percentage that even increased according to the current guideline where grade would be decisive for aCT in 10,869 (35.2%) patients. Also in current practice, the indication for adjuvant endocrine therapy (aET) would be based on grade in 9173 (29.7%) patients. Finally, as patients with lower-grade tumors receive aCT significantly less often, grade was also decisive in tailoring aCT de-escalation. CONCLUSIONS: In the largest study published so far we illustrate the increasing importance of histologic grade in tailoring adjuvant systemic breast cancer therapy. Next to playing a key-role in aCT-indication and de-escalation, the role of grading has expanded to the indication for aET. Optimizing histologic grading by pathologists is urgently needed to diminish the risk of worse patient outcome due to non-optimal treatment.

Long-term dietary sodium, potassium and fluid intake; exploring potential novel risk factors for renal cell cancer in the Netherlands Cohort Study on diet and cancer.

BACKGROUND: As sodium, potassium and fluid intake are related to hypertension, an established risk factor for renal cell cancer (RCC), they may be independent risk factors for RCC. METHODS: The Netherlands Cohort Study (NLCS) with case-cohort design included 120,852 participants aged 55-69 years. At baseline, diet and lifestyle were assessed with questionnaires. After 17.3 years of follow-up, 485 RCC cases and 4438 subcohort members were available for analyses. RESULTS: Sodium intake increased RCC risk (P-trend=0.03), whereas fluid and potassium intake did not. For high sodium and low fluid intake, the RCC risk additionally increased (P-interaction=0.02). CONCLUSION: Sodium intake is a potential risk factor for RCC, particularly if fluid consumption is low.