title: Prognostic risk factors for treatment decision in pT1a,b N0M0 HER2-positive breast cancers.
abstract: Although outcomes for women with breast cancers may vary by biologic subtype, patients with T1a,b N0M0 tumors have an excellent prognosis across all subgroups. HER2 overexpression occurs in 15-20% of primary breast tumors, and is associated with diminished disease-free and overall survival. The anti-HER2 monoclonal antibody trastuzumab in combination with chemotherapy is an effective treatment for all stages of HER2 positive breast cancer (bc). However, the absolute benefit decreases as the risk of recurrence lessens and no available randomized adjuvant trial has evaluated the role of trastuzumab in women with pT1a,b N0M0, HER2-positive breast tumors. These findings may explain the debate about the appropriate indication for adjuvant chemotherapy plus trastuzumab in this setting of patients. The aim of this review was to describe known and novel prognostic risk factors to be used for tailored treatment decision in pT1a,b N0M0 HER2-positive tumors. Whether patients with small HER2-positive bc may be suitable for (chemo)therapy reduction strategies, the current available data cannot exclude the need for a more aggressive treatment in a small subset of these subjects. Novel clinical prognostic factors such as interval cancer (IC) detection may help to address this clinically important controversy. A multicenter population-based cancer registry study is currently evaluating whether IC detection may identify patients with pT1a N0M0 HER2-positive tumors in whom the rate of recurrence justifies consideration for use of conventional, trastuzumab-based chemotherapy regimens.
authors.affiliation: Medical Oncology Unit and Cancer Registry of Parma Province, University Hospital of Parma, Italy. Electronic address: antoninomusolino@hotmail.com.
authors.forename: Antonino
authors.initials: A
authors.lastname: Musolino
authors.affiliation: Medical Oncology Unit and Cancer Registry of Parma Province, University Hospital of Parma, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Boggiani
authors.affiliation: Medical Oncology Unit and Cancer Registry of Parma Province, University Hospital of Parma, Italy.
authors.forename: Angelica
authors.initials: A
authors.lastname: Sikokis
authors.affiliation: Medical Oncology Unit and Cancer Registry of Parma Province, University Hospital of Parma, Italy.
authors.forename: Anita
authors.initials: A
authors.lastname: Rimanti
authors.affiliation: Medical Oncology Unit and Cancer Registry of Parma Province, University Hospital of Parma, Italy.
authors.forename: Benedetta
authors.initials: B
authors.lastname: Pellegrino
authors.affiliation: Romagna Tumor Registry, Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori, IRCCS, Meldola, Italy.
authors.forename: Rosa
authors.initials: R
authors.lastname: Vattiato
authors.affiliation: Medical Oncology Unit and Cancer Registry of Parma Province, University Hospital of Parma, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Sgargi
authors.affiliation: Romagna Tumor Registry, Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori, IRCCS, Meldola, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Falcini
authors.affiliation: Research and Innovation Unit, University Hospital of Parma, Italy.
authors.forename: Caterina
authors.initials: C
authors.lastname: Caminiti
authors.affiliation: Medical Oncology Unit and Cancer Registry of Parma Province, University Hospital of Parma, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Michiara
authors.affiliation: Medical Oncology Unit and Cancer Registry of Parma Province, University Hospital of Parma, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Leonardi
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology; D001943:Breast Neoplasms / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology; D017024:Chemotherapy, Adjuvant / Q000379:methods; D000066491:Clinical Decision-Making; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis / Q000517:prevention & control; D009367:Neoplasm Staging; D011379:Prognosis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D000068878:Trastuzumab / Q000494:pharmacology*
chemical_list: D000970:Antineoplastic Agents; D018719:Erb-b2 Receptor Tyrosine Kinases; D000068878:Trastuzumab
keywords: Breast cancer; HER2-positive; Interval cancer risk; Prognostic factors; pT1a,b