The dissertation of Tiina Lehtimäki demonstrates the importance of detection method in the long-term prognosis of breast cancers

The doctoral dissertation of M.D. Tiina Lehtimäki to be publicly examined on 8th November 2013 concentrates on the long-term prognosis of breast cancers. She has compared breast cancers detected at screening mammography to cancers found by other methods. This is an important research area, not least because of the fact that breast cancer is still the leading cause of cancer death among women despite the significant improvements in survival.

Tiina Lehtimäki works as a radiologist in HUS. She has done her M.D. Ph.D. thesis at the Institute for Molecular Medicine Finland (FIMM) and in the Department of Oncology, Helsinki University Central Hospital. Her dissertation, Screen-detected breast cancer and prognosis, was supervised by Docent Johan Lundin and Academy Professor Heikki Joensuu. The thesis consists of four publications.

The thesis work is based on a FinProg patient cohort ( This cohort consists of nearly 3,000 breast cancer patients diagnosed in Finland in 1991-92. Tiina has had a major role in designing, organizing and collecting this valuable database that contains both clinical and long-term survival information as well as pathological tumor samples. She visited each of the five University Hospitals in Finland and collected each patient’s histological tumor samples whenever available. Furthermore, she has updated the survival data several times during the follow-up time.

In her thesis, Tiina compared the biological profiles of screen-detected breast cancers to non-screen-detected cancers and showed that the molecular subtypes associated with favorable survival rates were more frequent in screen-detected breast cancers. She was also able to show that patients with screen-detected breast cancer had significantly better survival compared with patients with non-screen-detected cancer. Importantly, this advantage persisted over a 15-year follow-up period and it could not be entirely explained by the biological factors investigated.

-It’s assumable that this survival advantage is explained by some other, still unknown factors, Tiina explains.

-These factors will hopefully be identified in the future but before that, the method of detection should be taken into account in risk estimations and in individual therapy decisions.

- Based on the FinProg database our group has also developed a Web-based case-match survival estimation model freely available to clinicians. The model can aid physicians in estimating the risk of disease recurrence and thus be of value in the clinical decision-making.

Since the last round of updating the FinProg survival data has just been completed, there any new exciting analyzes waiting to be performed. In the near future, Tiina is going to look at the recurrence rates.

The public examination of Tiina Lehtimäki’s doctoral dissertation will take place on 8th November 2013 at 12 o´clock in Biomedicum Helsinki (Haartmaninkatu 8), Lecture Hall 3. The opponent is Docent, M.D., Ph.D. Minna Tanner, Tampere University Central Hospital and the custos Academy Professor Heikki Joensuu, Department of Pathology, University of Helsinki.

Link to e-thesis

Suomenkielinen lehdistötiedote