Abstract 1312
Background
Predictive online calculators are used by clinicians as decision aids in early breast cancer (EBC). While use statistics for these calculators have not been published, as of 2017 NHS Predict was being accessed more than 20,000 times a month. These predictive tools have not had accuracy & benefit of use prospectively confirmed in EBC, yet use of calculators has been encouraged in EBC guidelines. It is important to understand the populations informing model development & validation, to understand how data bias may impact predictions in under-represented subpopulations. This work sought to elucidate the risk of bias in model development & validation for 3 online EBC calculators (NHS Predict, Adjuvant! & Cancermath), in an effort to highlight sub-populations where calculated risk & therefore treatment benefit estimates may be less reliable.
Methods
A literature search was conducted in PubMed, search terms were “predict*” “adjuvant” “breast” & “algorithm”. Results were screened for relevance to the three predictive tools under scrutiny & additional references were extracted from relevant papers. Using a modified CHARMS checklist, the relevant sections of the development & validation papers were extracted.
Results
6 development & 24 validation papers were reviewed as summarised in the TableTable:
264P
Predict | Adjuvant | Cancermath | |
---|---|---|---|
Development population size & date range | 5694 1977-2008 | 37,968 1977-2007 | 499,724 1977-2007 |
Aged <35 in development population | 2% (111) | 0 | >0.5% |
Aged >65 in development population | 32% (1781) | 0 | >17% |
Tumour size >5cm in development population | 5% (287) | 0 | 0 |
Number of validation studies | 10 | 13 | 3 |
% retrospective | 100 | 100 | 100 |
Total number of patients in validation studies | 19,864 | 19,618 | 11,203 |
Age >65 in validations | 35% (7134) | 42% (8313) | 40% (4519) |
Age <35 in validations | 16% (3235) | 8% (1518) | 9% (1007) |
Tumour size >5cm in validations | 5% (287) | 5% (1015) | 6% (634) |
Universal exclusions | Multi-focal, inflammatory, male | Multi-focal, inflammatory, male | Multi-focal, inflammatory, male |
Neoadjuvant chemotherapy not an exclusion | 1 study (121 patients) | 0 | 0 |
Overall conclusions of validation authors | Earlier versions under-predicted mortality in women <35 Poor performance in tumours >5cm. | Poor performance in general in: <35 and >65 More advanced disease Malay ethnicity Overly optimistic survival predictions across subgroups in UK population. | Poor performance in < 35 Systematically under-predicted mortality, especially for ER-negative tumours. |
Conclusions
All 3 predictive tools have under-represented groups in their development cohorts, specifically those under 35 & over 65 years old, as well as larger tumours. Validation studies consistently demonstrate worse performance in these groups. However, due to inconsistent methodology in validation studies, quantitating the summary performance within & across tools is difficult. These predictive tools should be used with caution in under-represented populations. More work is required to look at clinical utility of tools as well as their statistical performance.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
4250 - Phase II study of avelumab in combination with cetuximab as a rechallenge strategy in pre-treated RAS wild type metastatic colorectal cancer patients: CAVE (cetuximab-avelumab) Colon.
Presenter: Erika Martinelli
Session: Poster Display session 2
Resources:
Abstract
5234 - The ORCHESTRA trial; A phase III trial of adding tumor debulking to systemic therapy versus systemic therapy alone in multi-organ metastatic colorectal cancer (mCRC).
Presenter: Lotte Bakkerus
Session: Poster Display session 2
Resources:
Abstract
5294 - EMERGE: Epigenetic Modulation of the Immune Response in Gastrointestinal cancers
Presenter: Elizabeth Cartwright
Session: Poster Display session 2
Resources:
Abstract
913 - Phase III, international, multicenter, randomized, open-label trial of adjuvant nab-paclitaxel plus gemcitabine (nab-P/G) vs gemcitabine (G) alone for surgically resected pancreatic adenocarcinoma (APACT): subgroup analyses
Presenter: Margaret Tempero
Session: Poster Display session 2
Resources:
Abstract
1668 - FOLFIRINOX in locally advanced (LA) and borderline resectable (BR) pancreatic adenocarcinoma : update of the AGEO cohort.
Presenter: Edouard Auclin
Session: Poster Display session 2
Resources:
Abstract
2559 - Impact of adjuvant treatment with nab-paclitaxel and gemcitabine (nab-P+GEM) vs gemcitabine alone (GEM) on health-related quality of life (QoL) in patients (pts) with surgically resected pancreatic adenocarcinoma (PA) in the Adjuvant Pancreatic Adenocarcinoma Clinical Trial (APACT)
Presenter: Hanno Riess
Session: Poster Display session 2
Resources:
Abstract
4897 - Early detection of pancreatic ductal adenocarcinoma using methylation signatures in circulating tumor DNA
Presenter: Xiao-ding Liu
Session: Poster Display session 2
Resources:
Abstract
1755 - Evaluation of minimal important difference (MID) for the European Organisation for Research and Treatment of Cancer (EORTC) Pancreatic Cancer Module (PAN26) in patients with surgically resected pancreatic adenocarcinoma
Presenter: Michele Reni
Session: Poster Display session 2
Resources:
Abstract
2876 - Multispectral analysis of lymphocyte complexity in periampullary adenocarcinoma
Presenter: Sebastian Lundgren
Session: Poster Display session 2
Resources:
Abstract
1902 - Phase II trial of preoperative modified FOLFIRINOX (mFOLFIRINOX) followed by postoperative gemcitabine (GEM) in patients (pts) with borderline resectable (BR) and locally advanced (LA) pancreatic ductal adenocarcinoma (PDAC)
Presenter: Jae Ho Jeong
Session: Poster Display session 2
Resources:
Abstract