Breast cancer: Towards individualized therapy

Breast cancer is the most common cancer among the female population. One in eight women develops a malignant tumor of the breast during her lifetime. However, breast cancers are never the same. In fact, breast cancer has a variety of subtypes, which have to be treated differently. "And it gets even more complicated in cases of advanced breast cancer that has already metastasized," says Peter Lichter, DKFZ and NCT Heidelberg. "Then we find larger differences not only among patients but also between individual cancer cells in one and the same patient." And this, he added, is what ultimately makes it so difficult to treat patients whose cancer has already seeded metastases.

The reason for this diversity is the fact that cancer arises from a wide variety of genetic alterations. Their exact type differs from one individual patient to the next. But it is precisely these genetic alterations which determine the course of the disease and the therapy that promises the best outcomes in the individual case. Within a study entitled CATCH (Comprehensive Assessment of Clinical Features and Biomarkers To Identify Patients with Advanced or Metastatic Breast Cancer for Marker Driven Trials in Humans), scientists and physicians led by Lichter and Andreas Schneeweiss, NCT and Heidelberg University Hospital, are now taking a closer look at this genetic diversity of breast cancer cells with the goal of offering individually tailored therapy to affected women in the future.

In a first step, Lichter and his team analyze tissue samples of metastases from patients with advanced breast cancer. In this way, the scientists first generate a genetic profile of each study participant. "In this way, we can identify individual differences in breast cancer cases much more precisely than it has been possible up to now," says molecular geneticist Lichter.

In a second step, oncologists led by Schneeweiss use this profile as a basis to select a therapy for the individual patient. Depending on what is needed, this may be an established standard therapy or a substance that is approved for other indications but also shows promise for treating the individual breast cancer type – a practice known as off-label use. Additionally, innovative treatment methods that are still in the scientific testing stage may also be applied. "A special feature of our study is that apart from this wide range of therapy methods to choose from, the study also includes only patients who are being treated here in our hospital," Schneeweis explained. "As a result, genetic analysis and treatment go hand in hand and we can react very quickly and adjust therapy – depending on how the patient responds to the treatment."

More than 130 patients have been included in the study so far. Part of the participants by now receives customized treatment that has been chosen according to the genetic profile of their metastatic tumor. "It is still early for success reports," says Schneeweiss. But he reveals that in a number of patients it is already observable that they are responding to the treatment and their state is improving. "And we are talking about patients in whom we could raise less hopes for recovery with conventional approaches."

The present pilot trial is restricted to the treatment of patients whose breast cancer has advanced to a stage where the main goal of therapy is to slow down further progression of the disease. "But in future, we also plan to include patients in early stages and at high risk of an aggressive course with metastatic spread," Schneeweiss explained. "If we succeed in improving the chances of cure and lowering relapse rates in these patients with our approach, then we can claim a true success in breast cancer therapy."

Contact for patients and referring physicians:
Patientenzentrum2.nct@med.uni-heidelberg.de