The N4+ study was conducted
at ten centres in the Netherlands by Prof. Sjoerd Rodenhuis
(Netherlands Cancer Institute) and Prof. Liesbeth de Vries (UMCG)
from 1993 to 1999. The study investigated the effectiveness of
high-dose chemotherapy compared with conventional dose chemotherapy
in 885 women with breast cancer and at least four positive lymph
nodes in the armpit.
To allow the
blood count to recover after high-dose chemotherapy the treatment
was combined with an autologous stem cell transplant, where the
patients' own stem cells were used.
Tessa Steenbruggen says:
"The 20-year follow-up shows a significant improvement in survival
after high-dose chemotherapy in patients with ten or more affected
lymph nodes in the armpit and a strong indication of improved
survival in patients with triple negative breast cancer.
Unfortunately, the latter group is slightly too small to draw
definite conclusions, but it is certainly impressive that 15% more
women have survived 20 years after high-dose chemotherapy than
after conventional dose chemotherapy."
Furthermore, the incidence
of secondary cancers or serious cardiovascular diseases does not
appear to increase after high-dose chemotherapy. These are the
feared side effects of administering high-dose chemotherapy. The
data underlines the importance of further research on high-dose
chemotherapy in patients with high-risk (stage 3) breast cancer,
such as the Dutch SUBITO study currently being conducted.
Thanks to the excellent
documentation of the study together with the cancer register and
PALGA pathology database, almost complete data is available for a
period of 20 years. Lars Steggink says: "These national records
offer a unique opportunity to collect the long-running follow-up
data of patients, which is vital to the continued improvement of
our breast cancer care".