TY - JOUR
T1 - Comparison of hazard models with and without consideration of competing risks to assess the effect of neoadjuvant chemotherapy on locoregional recurrence among breast cancer patients
AU - Pathak, Mona
AU - Deo, Surya Narayana V.S.
AU - Dwivedi, Sada Nand
AU - Vishnubhatla, Sreenivas
AU - Thakur, Bhaskar
N1 - Funding Information:
This study was not funded by any external funding agency. It is part of Ph.D. work of the first author, Dr. Mona Pathak.
Publisher Copyright:
© 2020 Journal of Cancer Research and Therapeutics.
PY - 2021/7/1
Y1 - 2021/7/1
N2 - Context: While analyzing locoregional recurrences (LRRs), it is necessary to consider distant metastasis as a competing event. Because, later one is more fatal than LRR. It may change ongoing treatment of breast cancer and may alter the chance of LRR. Although some earlier studies assessed the effect of neoadjuvant chemotherapy (NACT) on LRR, they did not use competing risk regression model for it. Aims: To identify the risk factors and predict LRR using competing risk hazard model and to compare them with those using conventional hazard model. Settings and Design: This was a retrospective study from a tertiary care cancer hospital in India. Subjects and Methods: Data of 2114 breast cancer patients undergoing surgery were used from patient’s record files (1993–2014). Statistical Analysis: Fine and Gray competing risk regression was used to model time from surgery to LRR, considering distant metastasis and death as the competing events. Further, cause-specific Cox regression was used to model time from surgery to LRR without considering competing risk. Results: Greater than ten positive nodes (hazard ratio [HR] [95% confidence interval (CI)]: 2.19 [1.18–4.03]), skin involvement (HR [95% CI]: 2.75 [1.50–5.05]), NACT (HR [95% CI]: 1.90 [1.06–3.40]), invasive tumor in inner quadrant (HR [95% CI]: 1.78 [0.98–3.24]), and postoperative radiotherapy (HR [95% CI]: 0.52 [0.29–0.94]) were found to be significantly associated with LRR. However, conventional survival analysis ignoring competing risk overestimated cumulative incidence function and underestimated survival. Competing risk regression provided relatively more precise CI. Conclusions: Competing risks, if any, need to be incorporated in the survival analysis. NACT was found to be associated with higher risk for LRR, which may be because of administering it mainly to patients with bad prognosis.
AB - Context: While analyzing locoregional recurrences (LRRs), it is necessary to consider distant metastasis as a competing event. Because, later one is more fatal than LRR. It may change ongoing treatment of breast cancer and may alter the chance of LRR. Although some earlier studies assessed the effect of neoadjuvant chemotherapy (NACT) on LRR, they did not use competing risk regression model for it. Aims: To identify the risk factors and predict LRR using competing risk hazard model and to compare them with those using conventional hazard model. Settings and Design: This was a retrospective study from a tertiary care cancer hospital in India. Subjects and Methods: Data of 2114 breast cancer patients undergoing surgery were used from patient’s record files (1993–2014). Statistical Analysis: Fine and Gray competing risk regression was used to model time from surgery to LRR, considering distant metastasis and death as the competing events. Further, cause-specific Cox regression was used to model time from surgery to LRR without considering competing risk. Results: Greater than ten positive nodes (hazard ratio [HR] [95% confidence interval (CI)]: 2.19 [1.18–4.03]), skin involvement (HR [95% CI]: 2.75 [1.50–5.05]), NACT (HR [95% CI]: 1.90 [1.06–3.40]), invasive tumor in inner quadrant (HR [95% CI]: 1.78 [0.98–3.24]), and postoperative radiotherapy (HR [95% CI]: 0.52 [0.29–0.94]) were found to be significantly associated with LRR. However, conventional survival analysis ignoring competing risk overestimated cumulative incidence function and underestimated survival. Competing risk regression provided relatively more precise CI. Conclusions: Competing risks, if any, need to be incorporated in the survival analysis. NACT was found to be associated with higher risk for LRR, which may be because of administering it mainly to patients with bad prognosis.
KW - Cause-specific hazard model
KW - Cumulative incidence competing risk
KW - Distant metastasis
KW - Fine and Gray model
KW - Sub-distribution hazard model
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U2 - 10.4103/jcrt.JCRT_49_19
DO - 10.4103/jcrt.JCRT_49_19
M3 - Article
C2 - 34528552
AN - SCOPUS:85115714054
SN - 0973-1482
VL - 17
SP - 982
EP - 987
JO - Journal of Cancer Research and Therapeutics
JF - Journal of Cancer Research and Therapeutics
IS - 4
ER -