Public Defence: Olaf Johan Hartmann-Johnsen Olaf Johan Hartmann-Johnsen at Institute of Clinical Medicine will be defending the thesis “Breast-conserving therapy is better than mastectomy Evidence based on registry data from Norway” for the degree of PhD (Philosophiae Doctor).

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Photo: Azhar Abbas

Trial Lecture – time and place

See Trial Lecture.

Adjudication committee

  • First opponent: Professor Peer Christiansen, Aarhus UniversitySecond opponent:
  • Professor Sabine Siesling, University of Twente
  • Third member and chair of the evaluation committee: Professor Egil Johnsen, University of Oslo

Chair of the Defence

Professor Torill Sauer, University of Oslo

Principal Supervisor

Head of Departement Jan F. Nygård, Cancer Registry of Norway


Since breast-conserving surgery was accepted as a treatment for breast cancer in the late 1980s, it has been assumed that survival gains are the same whether preserving or removing the breast. The thesis "Breast-conserving therapy is better than mastectomy, based on registry data from Norway" shows that women who are operated with breast conserving therapy have better survival than those who remove the breast.

Article I, the first study based on data outside the United States, shows that breast preservers have better breast cancer survival than those who remove the breast.

Article II is based on women participating in the mammography screening program. Here one has identified a group where it is particularly beneficial with breast preserving. If the tumor is 2 cm or less and there are 1 to 3 lymph nodes with cancer, breast preservers have almost 3 times better breast cancer survival than those who remove the breast.

Based on Articles I, II and now several similar European studies, it seems less credible that the survival benefit is equal to whether one chooses breast preservation or removal of the breast. In "UpToDate" where Article I is referred to, breast conserving therapy is recommended as first choice of treatment.

We do not know why breast preservation is better. Article II promotes a hypothesis that chemotherapy that destroys residual breast cancer cells can trigger a favourable immune response. It is possible that radiation therapy to residual breast tissue and axilla may provide a similar response.

Detailed information on diagnosis, treatment and follow-up is needed to identify a cause that may explain the findings in Articles I and II. The Norwegian Breast Cancer Group with the cancer register has established the Norwegian quality register for breast cancer. To increase and motivate fore data collection, article III describes how submitted data to the cancer registry can be used for European certification of hospitals that treat breast cancer in Norway.

Additional information

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Published Sep. 13, 2019 2:42 PM - Last modified Sep. 20, 2019 12:28 PM