The role of chemotherapeutic drugs in the evaluation of breast tumour response to chemotherapy using serial FDG-PET.
BACKGROUND
The aims of this study were to investigate whether drug sequence (docetaxel followed by anthracyclines or the drugs in reverse order) affects changes in the maximal standard uptake volume (SUVmax) on [18F]fluorodeoxyglucose positron emission tomography (FDG-PET) during neoadjuvant chemotherapy in women with locally advanced breast cancer.


METHODS
Women were randomly assigned to receive either drug sequence, and FDG-PET scans were taken at baseline, after four cycles and after eight cycles of chemotherapy. Tumour response to chemotherapy was evaluated based on histology from a surgical specimen collected upon completion of chemotherapy.


RESULTS
Sixty women were enrolled into the study. Thirty-one received docetaxel followed by anthracyclines (Arm A) and 29 received drugs in the reverse order (Arm B). Most women (83%) had ductal carcinoma and 10 women (17%) had lobular or lobular/ductal carcinoma. All but one tumour were downstaged during therapy. Overall, there was no significant difference in response between the two drug regimens. However, women in Arm B who achieved complete pathological response had mean FDG-PET SUVmax reduction of 87.7% after four cycles, in contrast to those who had no or minor pathological response. These women recorded mean SUVmax reductions of only 27% (P < 0.01). Women in Arm A showed no significant difference in SUVmax response according to pathological response. Sensitivity, specificity, accuracy and positive and negative predictive values were highest in women in Arm B.


CONCLUSIONS
Our results show that SUVmax uptake by breast tumours during chemotherapy can be dependent on the drugs used. Care must be taken when interpreting FDG-PET in settings where patients receive varied drug protocols.
Schneider-Kolsky
Michal E
ME
Department of Medical Imaging and Radiation Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Wellington Road, Victoria 3800, Australia. michal.schneider-kolsky@med.monash.edu.au
Hart
Stewart
S
Fox
Jane
J
Midolo
Peter
P
Stuckey
John
J
Hofman
Michael
M
Ganju
Vinod
V
D000328:Adult; D000368:Aged; D018943:Anthracyclines / Q000008:administration & dosage; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000188:drug therapy; D018270:Carcinoma, Ductal, Breast / Q000175:diagnosis* / Q000188:drug therapy; D018275:Carcinoma, Lobular / Q000175:diagnosis* / Q000188:drug therapy; D017024:Chemotherapy, Adjuvant; D000077143:Docetaxel; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D011960:Receptors, Estrogen / Q000378:metabolism; D011980:Receptors, Progesterone / Q000378:metabolism; D015996:Survival Rate; D043823:Taxoids / Q000008:administration & dosage; D016896:Treatment Outcome
D018943:Anthracyclines; D000077143:Docetaxel; D019788:Fluorodeoxyglucose F18; D019275:Radiopharmaceuticals; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D043823:Taxoids