Scientists and patients have long looked to discover whether tumors in dense breasts are harder to treat than the rest. After careful analyses, doctors claim tumors in dense breasts are harder to spot in mammograms, but this doesn’t make them less likely to be treated, according to the Associated Press.

The results of the mammograms are often difficult to interpret if the patient has what doctors call “dense breast”, that is, breasts which are entirely made out of milk-producing and connective tissue instead of fat. Given these circumstances, incipient tumors may go unidentified and patients could live with the wrong impression that they are healthy. Health organizations urge institutions to tell patients if they have dense breasts, so they could perform more complex medical check-ups.

Since tumors in dense breasts are discovered much later than those in fatty tissues, scientists have jumped to the conclusion that dense breast tumors are harder to treat than the others. A recent study performed by the Cancer Institute on 9,000 patients proves that patients with dense breast tumors are not more likely to die than the other patients. Co-author Dr. Karla Kerlikowske of the University of California, San Francisco reassured everyone that tumors in dense breasts are actually very responsive to treatment even if they are discovered at a later state.

Further analyses reported that certain factors can lead to mortality in the case of women with less dense breasts. The patients’ condition can worsen if they also suffer from obesity or if their tumors are discovered when they are very big. Doctors were unable to find an explanation for this fact, but they have, nevertheless, speculated that hormones accompanying obesity could influence the evolution of the disease in a negative way.

Distinguishing between cancerous spots and dense tissue is difficult because they both appear as white on mammograms. New state laws could constrain doctors to inform their patients if they have dense tissue or not.