Diagnosis and Treatment of Breast Cancer. Is there a place for PET scan ?

1
Diagnosis and Treatment of Breast Cancer.Is
there a place for PET scan ?

• Professeur Alain Brémond
• Centre Régional de Lutte Contre le Cancer
• Université Claude Bernard Lyon I
• Lyon - France

2
The two steps of diagnosis

• Perception  Is there any abnormality on the
  mammography ?
• Analysis  Which of the abnormalities is a
  cancer?

3
Sensitivity of mammography

• Overall 80
• Fatty breasts
• 95
• Lower limit in the size of a detectable tumor 5
  mm
• Dense breasts
• 70
• Lower limit 10 to 20 mm (sometimes more).

4
What could be the role of PET scan ?

• The sensitivity of the PET scan does not depend
  on the breast density.
• Issues
• Localization of tumors otherwise not seen on
  mammography or ultrasonography.
• Is core biopsy directed by PET scan possible ?

5
Evaluation of the lymph nodes invasion .

• Axillary dissection is the standard
• But side effects are frequent
• Lymphoedema 6
• Arm swelling 25 to 40
• Pain in axilla and/or shoulder 50 to 60
• No benefit for the patient if there are no
  invaded nodes in the axilla.

6
What about Sentinel node biopsy?

• SNB is an alternative to axillary dissection for
  small tumors (less than 2.5 cm in diameter).
• But patients with invaded nodes have to be
  operated on a second time (That is in about 45
  of the cases).
• Could PET scan of the axilla select the patients
  with invaded nodes ?

7
PET studies to evaluate axillary lymph-node
status.Adapted from I.C. Smith (Eur J Surg Oncol)
 
  Adapted from I.C. Smith (Eur J Surg ).
Sensitivity and specificity of PET scan to assess
the axilla.
8
Selection for axillary node dissectionAND
(tumours lt 2,5 Cm in diameter)
PET / AND Positive Negative Total
Positive 36 (90) 10 46
Negative 4 50 (84) 54
Total 40 60 100
9
Pet scan as a selection tool?

• Suspicion of the involvement of the axillary
  lymph nodes. In this goal PET studies have shown
  a sensitivity which varies from 57 to 100 and a
  specificity going from 66 to 100 with means of
  89.8 and 84.3.
• SNB would be indicated for negative PET scans.
  This would reduce the number of unnecessary SNB.
  With these values the table has shown than among
  100 patients, 46 would have a positive axillary
  PET scan. Axillary dissection would be performed
  in these patients but in 10 patients the axilla
  would be free from cancer. Is this acceptable ?

10
Other indications

• Patients with large tumours can benefit from
  primary chemotherapy. In 50 of these cases a
  conservative treatment can be performed instead
  of a radical mastectomy. This is usually offered
  to the patient. Knowing the risk of having
  positive nodes in the axilla could be useful in
  the treatment choice.

11
Economic clues.

•  The costs of SNB is being measured in our
  institution.
• The costs of PET scan should be evaluated in
  comparison with SNB in a combined modality of
  evaluation of the axilla

12
Conclusions

• PET scan can be of interest in
• Screening in dense breast.
• Preoperative evaluation of the axilla
• Sensitivity and specificity of PET scan have to
  be improved for these indications.