Tumor size is an unreliable predictor of prognosis in basal-like breast cancers and does not correlate closely with lymph node status.
Larger breast tumors tend to be associated with a greater number of axillary lymph nodes involved with metastatic tumor than are smaller tumors. This rule may not fully apply in BRCA1-related breast cancers. We hypothesized that the rule also might not apply in basal-like breast cancers (BLBC), and further, that disruption of this relationship would impact on prognosis. In 1,324 non-BLBC (87.1% of 1520 tumors), after adjustment for grade, a strongly positive correlation between increasing tumor size and increasing number of lymph nodes involved by tumor was observed (P for trend <.001). The correlation was much weaker in 196 BLBC (12.9%) (P for trend = 0.58). Similarly, a worsening breast cancer-specific survival with increasing tumor size was observed in non-BLBC (P for trend <.001) but not in BLBC (P for trend = 0.43). The "size-nodes" relationship in BLBC is distinct and is similar to that seen in BRCA1-related breast cancer, further suggesting biological similarities between these sub-types of breast cancer. Moreover, tumor size is not a strong indicator of prognosis in BLBC.
Foulkes
William D
WD
Departments of Oncology and Human Genetics, McGill University, Montreal, QC, Canada. william.foulkes@mcgill.ca
Grainge
Matthew J
MJ
Rakha
Emad A
EA
Green
Andrew R
AR
Ellis
Ian O
IO
D001943:Breast Neoplasms / Q000401:mortality / Q000473:pathology*; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis / Q000473:pathology*; D009361:Neoplasm Invasiveness / Q000473:pathology; D009367:Neoplasm Staging; D011379:Prognosis; D016016:Proportional Hazards Models; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics; D011960:Receptors, Estrogen / Q000096:biosynthesis
D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; C508053:ERBB2 protein, human