30% of cancers don’t respond to current treatments

Over the past 20 years, personalized medicine has come to be seen as the best therapeutic strategy to fight certain types of tumors. In the period between 2010 and 2014 alone, 45 new drugs to treat specific cell lesions were approved. This type of treatment, along with surgery, can reduce or control tumors in some patients, but there are cases –approximately 30%– in which the tumor reappears after some time and the disease doesn’t respond to second or third rounds of treatment. In these cases, tumor cells learn to grow despite the medication, which is known as therapeutic resistance. This was the topic of the first B·Debate of the year, an initiative of Biocat and the “la Caixa” Foundation, held on 7 and 8 April at CosmoCaixa and co-organized by the Catalan Institute of Oncology (ICO) and the Vall d’Hebron Oncology Institute (VHIO).

“Unfortunately, as happens with most issues associated with cancer, there is no overarching answer (or at least we haven’t found it) because tumor cells are very flexible and evolve very quickly. This is why our strategy is a two-pronged attack, because the tumor can't withstand it as well as if we only attack on one front,” explained Joaquin Arribas, ICREA research professor and head of preclinical research at the Vall d’Hebron Oncology Institute (VHIO). Arribas was also scientific leader of this B·Debate with Miquel Àngel Pujana, head of the new ProCURE program to fight therapeutic resistance in cancer at the Catalan Institute of Oncology (ICO).

The event featured national experts including Manel Esteller, head of the IDIBELL Epigenetics and Cancer Biology Program, and Rafael Rosell, head of Medical Oncology at the ICO; as well as international experts like Sebastian Kreiter, researcher at the Johannes Gutenberg University in Germany, and Elaine Mardis, co-director of the McDonnell Genome Institute.

The debate focused in particular on patient survival, as in 1990 only 50% of people with cancer lived more than five years after being diagnosed and now the 5-year survival rate is approximately 67%. However there are still some tumors for which medicine hasn’t advanced much. For example, ovarian cancer is treated in exactly the same way it was 30 years ago, and the ever-changing cancer cells associated with this type of the disease have become resistant to current drugs. And pancreatic cancer, “which hardly responds to any sort of therapy has a survival rate similar to that of 50 years ago,” explained Arribas.

Pharmaceutical spending was another topic put to debate at the event, as a large part of the budget goes to research in this area. For example, Pujana explained, “in the case of the ICO, nearly half the budget for drugs went to counteract these resistances.” Plus, early diagnosis and longer treatment have also pushed up spending.

Nevertheless, many experts are now looking to oncological immunotherapy, a treatment that stimulates the patient’s own immune system to recognize tumor cells and fight them, to improve patient survival rates. “There are many more hurdles than expected in the fight against cancer, and we had probably underestimated them,” declared Arribas.