The studies in this thesis contribute to more accurate risk assessment and prognosis prediction for DCIS and to better response evaluation of IBC treatment.For the Ductal Carcinoma In Situ (DCIS)... Show moreThe studies in this thesis contribute to more accurate risk assessment and prognosis prediction for DCIS and to better response evaluation of IBC treatment.For the Ductal Carcinoma In Situ (DCIS) studies, unbiased cohorts were used within the international Grand Challenge PRECISION consortium, funded by Cancer Research UK and KWF Dutch Cancer Society. DCIS is graded as low-, intermediate-, or high-grade depending on how abnormal the DCIS-cells look like. However, we showed that pathologists often disagree on grade. To overcome this limitation, we found that almost all DCIS scored as non-high-grade by the majority of pathologists express the estrogen receptor (ER) and are negative for the growth factor receptor HER2, whereas high-grade DCIS is mixed in expression for ER and HER2. We also provided insights in the recurrence risks of DCIS after treatment. See also https://cancergrandchallenges.org/teams/precision.The studies on Invasive Breast Cancer (IBC) were performed on a hospital-based cohort. We found for example substantial variation in tumour response evaluation for HER2-positive IBC after pre-operative chemotherapy due to different guidelines used. For accurate outcome analysis, reducing such variation is mandatory. Therefore, we are working on reaching international consensus of response evaluation. Show less
Introduction: Optimized treatment of primary rectal cancer might have influenced treatment characteristics and outcome of locally recurrent rectal cancer (LRRC). Subgroup analysis of the Dutch TME... Show moreIntroduction: Optimized treatment of primary rectal cancer might have influenced treatment characteristics and outcome of locally recurrent rectal cancer (LRRC). Subgroup analysis of the Dutch TME trial showed that preoperative radiotherapy (PRT) for the primary tumour was an independent poor prognostic factor after diagnosis of LRRC. This cross-sectional population study aimed to evaluate treatment and overall survival (OS) of LRRC patients, stratified for prior preoperative radiotherapy (PRT) and intention of treatment of LRRC.Methods: All patients developing LRRC were selected from a collaborative Snapshot study on 2095 surgically treated rectal cancer patients from 71 Dutch hospitals in the year 2011. Cox proportional hazard analysis was performed to determine predictors for OS.Results: A total of 107 LRRC patients (5.1%) were included, of whom 88 (82%) underwent PRT for their primary tumour. LRRC was treated with initial curative intent in 31 patients (29%), with eventual resection in 20 patients (19%). Median OS was 22 and 8 months after curative and palliative intent treatment, respectively (p < 0.001). Initial CRM positivity and palliative intent treatment were associated with worse OS after LRRC, while prior PRT was not.Conclusions: This cross-sectional study revealed that rectal cancer patients, who underwent curative resection in the Netherlands in 2011 and subsequently developed local recurrence, were amenable for again curative intent treatment in 29%, with a corresponding median survival of 22 months. Prior PRT was not significantly associated with survival after diagnosis of LRRC. (C) 2019 Elsevier Ltd, BASO similar to The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved. Show less
Bone metastases of the long bones can cause pain and pathologic fractures. Local treatment consists of radiotherapy or surgical stabilisation. The most appropriate treatment depends on many factors... Show moreBone metastases of the long bones can cause pain and pathologic fractures. Local treatment consists of radiotherapy or surgical stabilisation. The most appropriate treatment depends on many factors, including the symptoms, the location and extent of the lesion, the wishes and expectations of the patient, and the expected remaining survival. Survival estimation of patients with symptomatic long bone metastases is crucial to prevent over- and undertreatment. This thesis aimed to develop a prognostic model for estimating survival in patients with cancer and symptomatic metastases of the long bones, evaluate current (surgical) treatment modalities and trends, and provide rationale for future prospective randomized trials. As a result, the OPTIModel was developed: an easy-to-use prognostic model that categorises patients into four clinically relevant survival categories based on only three variables (tumour type, Karnofsky Performance Score, visceral/brain metastases). To enable easy use of the model, an app was created (OPTIModel). Futhermore, this thesis shows that almost all treatments of pathologic fractures are based on expert opinion and small, retrospective cohorts, as opposed to large, prospective (randomized) trials, which is interesting in an era of evidence based medicine. This confirms the need of a prospective, multicenter cohort, which was designed and implemented accordingly. Show less
Prognostic factors are used for making treatment decisions regarding adjuvant systemic therapy. The major prognostic variables that are used in clinical practice are the number of positive axillary... Show morePrognostic factors are used for making treatment decisions regarding adjuvant systemic therapy. The major prognostic variables that are used in clinical practice are the number of positive axillary lymph nodes and tumour size. A number of other variables are associated with disease recurrence and survival as well. In particular UPA and PAI-1 appear to be strong prognostic variables. No differences in prognostic value of oestrogen receptor and progesterone receptor detected by immunocytochemical assay or enzyme immuno assay were found. In the study presented no significant association between mitotic counts and disease recurrence or survival was found, which was explained by the favourable tumour characteristics of the group of patients and the associated low number of events. Several tools have been developed to make individualised estimates of baseline prognosis and absolute survival benefit of adjuvant systemic therapy. Two of these tools, Adjuvant! and Numeracy, were compared. Adjuvant! was the preferred prognostic model. The administration of adjuvant chemotherapy concurrently with radiotherapy appeared too toxic. As anthracyclin-containing regimens have become standard for adjuvant chemotherapy in early breast cancer which are considered more toxic than the regimens studied the concurrent administration of adjuvant chemotherapy and radiotherapy is dissuaded. Show less
