HOUSTON, Tex -- November 2, 2009 -- Patients with early-stage breast
cancer and with HER2 positive tumours <= 1 cm are at significant risk of
recurrence of their disease, compared with those with early-stage disease who do
not express the aggressive protein, according to a study published today online
in the Journal of Clinical Oncology.
The findings of the study suggest that women with early-stage HER2 positive
breast cancer should be assessed for risk of recurrence and considered for
additional treatment.
"Our findings show that women with early stage HER2 positive breast cancer have
a 23% chance of recurrence. In contrast, the 5-year survival rate of all women
with such early-stage breast cancer is more than 90%," said Ana M. Gonzalez-Angulo,
MD, Department of Breast Medical Oncology and Systems Biology, The University of
Texas M. D. Anderson Cancer Center, Houston, Texas.
"The findings indicate that physicians need to consider offering these women
Herceptin-based therapy in the post-operative, or adjuvant setting," Dr.
Gonzalez-Angulo continued.
Current guidelines call for no additional therapy after surgery and radiation if
tumours are < 5 millimeters and Herceptin-based adjuvant therapy should be
discussed with patients if the tumours are from 6 to 10 millimeters, Dr.
Gonzalez-Angulo explained.
She said the number of patients with HER2 positive tumours <1 cm continues to
increase as breast cancer surveillance and early detection become increasingly
sophisticated.
"Before now, there's been no data regarding how to treat these women because
they were excluded from all the definitive trials confirming Herceptin's
benefit," she said. "This data strongly suggests that we need to rethink how we
treat early-stage breast cancer patients with HER2 positive tumours and likely
offer anti-HER2 therapy in the adjuvant setting."
For the retrospective study, researchers used M. D. Anderson's Breast Cancer
Research Database to analyse 965 patients treated between 1990 and 2002. All of
the patients' tumours were < 1 cm. Patients whose receptor status could not be
analysed and/or had received adjuvant chemotherapy or Herceptin at any time were
excluded. To validate the findings, a second cohort of 350 patients from
European institutions was also analysed.
Of the M. D. Anderson patient population, more than 10% (98 patients) had HER2
positive tumours. In addition, 77% were hormone-receptor positive and 13% were
triple receptor-negative.
In those analyzed with HER2 positive tumours, the 5-year, recurrence-free
survival was 77.1%; in contrast, HER2 negative patients' recurrence-free
survival was 93.7%. Five-year distant recurrence-free survival was 86.4% in
women with HER2 positive tumours compared with 97.2% in women with HER2-negative
tumours. Patients with HER2-positive tumours had 2.68 times higher risk of
recurrence and 5.3 times higher risk of distant recurrence than those with
HER2-negative tumours.
In addition, women with HER2-positive tumors had 5.09 times the risk of
recurrence and 7.81 times risk of distant recurrence than women with hormone
receptor-positive tumours.
The European subset confirmed the M. D. Anderson findings and showed
reproducibility, said Gonzalez-Angulo.
SOURCE: University of Texas M. D. Anderson Cancer Center
