New national recommendations for the treatment of pediatric differentiated thyroid carcinoma in the Netherlands

BACKGROUND

Currently, there are no European recommendations for the management of pediatric thyroid cancer. Other current international guidelines are not completely concordant. In addition, medical regulations differ between, for instance, the US and Europe. We aimed to develop new, easily accessible national recommendations for differentiated thyroid carcinoma (DTC) patients <18 years of age in the Netherlands as a first step toward a harmonized European Recommendation.

METHODS

A multidisciplinary working group was formed including pediatric and adult endocrinologists, a pediatric radiologist, a pathologist, endocrine surgeons, pediatric surgeons, pediatric oncologists, nuclear medicine physicians, a clinical geneticist and a patient representative. A systematic literature search was conducted for all existing guidelines and review articles for pediatric DTC from 2000 until February 2019. The Appraisal of Guidelines, Research and Evaluation (AGREE) instrument was used for assessing quality of the articles. All were compared to determine dis- and concordances. The American Thyroid Association (ATA) pediatric guideline 2015 was used as framework to develop specific Dutch recommendations. Discussion points based upon expert opinion and current treatment management of DTC in children in the Netherlands were identified and elaborated.

RESULTS

Based on the most recent evidence combined with expert opinion, a 2020 Dutch recommendation for pediatric DTC was written and published as an online interactive decision tree (www.oncoguide.nl).

CONCLUSION

Pediatric DTC requires a multidisciplinary approach. The 2020 Dutch Pediatric DTC Recommendation can be used as a starting point for the development of a collaborative European recommendation for treatment of pediatric DTC.

Prognostic factors for survival in metastatic breast cancer by hormone receptor status

Hormone receptor (HR) status is an important prognostic factor for patients with metastatic breast cancer (MBC) and is also correlated with other prognostic factors, such as initial lymph node status, HER2-Neu status and age. The prognostic value of these other factors, however, is unknown when stratified by HR positive versus HR negative patients. The aim of this study was to evaluate prognostic factors for MBC survival in relation to HR status. Dutch women diagnosed with breast cancer in 2003-2006 treated with curative intent who developed MBC within 5 years of follow-up were selected from the Netherlands cancer registry (N = 2,001). Independent prognostic factors for survival after metastatic occurrence were determined by multivariable Cox survival analyses stratified by HR status. Interactions between HR status and prognostic factors were determined. Median survival for MBC patients with HR negative (HR-) tumours was 8 months, compared to 19 months for HR positive (HR+) patients. The prognostic value of lymph node status, HER2-Neu status, adjuvant endocrine treatment and first-line palliative chemotherapy was dependent on HR status. Initial lymph node status was independently associated with survival in HR- patients, but not in HR+ patients. HER2-Neu positive status was associated with better survival in both HR+ and HR- patients, although the association was stronger in HR- patients. Similarly, patients treated with first-line palliative chemotherapy fared better, especially HR- patients. HR+ patients had worse survival if they had received adjuvant endocrine treatment. This study shows that the prognostic value of various factors depends on HR status in MBC. This information may help physicians to determine individual prognostic profiles and therapeutic strategies for MBC patients.

Increased risks of third primary cancers of non-breast origin among women with bilateral breast cancer

BACKGROUND

This study examined the risk of third cancer of non-breast origin (TNBC) among women with bilateral breast cancer (BBC; either synchronous or metachronous), focussing on the relation with breast cancer treatment.

METHODS

Risk was assessed, among 8752 Dutch women diagnosed with BBC between 1989 and 2008, using standardised incidence ratios (SIR) and Cox regression analyses to estimate the hazard ratio (HR) of TNBC for different treatment modalities.

RESULTS

Significant increased SIRs were observed for all TNBCs combined, haematological malignancies, stomach, colorectal, non-melanoma skin, lung, head and neck, endometrial, and ovarian cancer. A 10-fold increased risk was found for ovarian cancer among women younger than 50 years (SIR=10.0, 95% confidence interval (CI)=5.3-17.4). Radiotherapy was associated with increased risks of all TNBCs combined (HR=1.3; 95%CI=1.1-1.6, respectively). Endocrine therapy was associated with increased risks of all TNBCs combined (HR=1.2; 95%CI=1.0-1.5), haematological malignancies (HR=2.0; 95%CI=1.1-3.9), and head and neck cancer (HR=3.3; 95%CI=1.1-10.4). After chemotherapy decreased risks were found for all TNBCs combined (HR=0.63; 95%CI=0.5-0.87).

CONCLUSION

Increased risk of TNBC could be influenced by genetic factors (ovarian cancer) or an effect of treatment (radiotherapy and endocrine therapy). More insight in the TNBC risk should further optimise and individualise treatment and surveillance protocols in (young) women with BBC.

P1-08-11: Differences in Recurrence Dynamics between Lobular and Ductal Invasive Breast Cancer

Introduction: Many studies investigated disease free survival after breast cancer treatment. A few studies focused on patterns of recurrence risk over time. However, they ignored the impact of histology. This study aimed to determine differences in recurrence dynamics on population-based data between patients with a ductal breast cancer (DBC) and lobular breast cancer (LBC).

Methods: All surgically treated women diagnosed in 2003–2004 with invasive DBC or LBC, with no distant metastases or second primary breast cancer were selected from the Netherlands Cancer Registry. The recurrence patterns were studied using the life-table method to estimate the hazard rate for the first recurrence with the worst prognosis (locoregional (LRR) or distant metastases), that is, the conditional probability of manifesting recurrence in a time interval, given that the patient is clinically free of any recurrence at the beginning of the interval. The wilcoxon test was used to determine differences in recurrence patterns between DBC and LBC.

Results: Of 16,231 women identified, 87% had DBC and 13% LBC. LRR was found in 4% of the DBC and in 3% of the LBC patients, whereas metastases were found in 11% and 10% of patients, respectively. Notably, in DBC patients a peak in recurrence rate was seen between 1–2 years after diagnosis, both for LRR and distant metastases. On the other hand, in LBC patients the recurrence pattern did not show major peaks: after 2 years the curve revealed an almost steady level for LRR and distant metastases. This recurrence pattern was significantly different (P=&lt;0.001). Moreover, the influence of age, stage and treatment on recurrence differed between DBC and LBC. We also noticed a difference in localization of metastasis.

Conclusion: Our study showed an overall equal number of recurrences after DBC and LBC, but with a totally different recurrence pattern, which could have implications on follow-up of the patients.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-08-11.

Evaluation of the adherence to follow-up care guidelines for women with breast cancer

PURPOSE

To evaluate adherence with follow-up criteria as suggested by the national guideline for breast cancer patients.

METHOD

Patients diagnosed with breast cancer in 2003 in two hospitals were identified from the Netherlands Cancer Registry (n = 198). Compliance with the guideline was assessed retrospectively by extracting follow-up care data from patient files for a period of five years.

RESULTS

Follow-up data were available for 196 patients. In the first year of follow-up, fewer consultations were performed compared to guideline standards. In the second through the fifth year of follow-up, more consultations were performed, with nearly double the number of consultations in the third until the fifth year compared to the guideline (p < 0.05). This excess usage was mainly associated with the fact that women had received radiotherapy (p < 0.01). Physical examinations were performed during 97 percent of consultations. Mammograms were performed slightly less often than suggested.

CONCLUSIONS

Among women receiving follow-up care after breast cancer, more consultations were provided compared to the guideline recommendations. Mammograms were performed slightly less often than recommended. With regard to the performance of physical examinations, the guideline was followed.