The cLBT was used to follow 57 dogs during and after treatment.1 196 sequential serum samples were collected over a 4 year period (2008-2012) from 57 dogs undergoing chemotherapy treatment for lymphoma visiting two veterinary referral practices. For each dog included in the study, excess blood taken as part of the diagnostic evaluation around the time of confirmed diagnosis by cytology or histology but prior to commencement of treatment (week 0 samples). Additionally, repeat excess blood samples were obtained as part of routine assessment at each subsequent visit until time of death. Canine lymphoma remission was assessed by the veterinarian using WHO guidelines which defined three states: complete remission (CR) where there was complete disappearance of lymphadenopathy and other clinical evidence; partial remission (PR) where at least 50% decrease was observed in the measurement of the affected lymph nodes (with no other nodes being involved); and progressive disease (PD) where, following treatment, a patient failed to attain the criteria needed for CR or PR and an increase of more than 50% in the size of the lymph nodes occurred.
In our study disease recurrence was confirmed by cytology in all cases. Remission could not be confirmed by fine needle aspirates (FNA), due to the difficulty of aspirating a normal lymph node and the diagnosis had to be based on clinician’s assessment.
cLBT assessment of canine lymphoma remission and recurrence compared well with clinicians’ assessment and differentiated dogs in remission and those with recurring disease before appearance of lymphadenopathy (p<0.001).
The cLBT demonstrated prognostic potential based on pre-treatment values on dogs with shorter survival times and on those achieving the lowest cLBT score during treatment that showed longer survival times.
The cLBT data presented in our study indicate a potential prognostic value both at the point of diagnosis from the initial cLBT value and during treatment from the lowest cLBT score achieved by chemotherapy.
Dogs showing very high cLBT values at the time of diagnosis lived for significantly shorter times than those dogs that had lower week 0 cLBT values. The study demonstrated that differences in longevity was not due to either group being biased towards T or B cell lymphoma.
It was also noted that the lower the cLBT value achieved during treatment, the greater the survival time. Dogs which achieved a minimum cLBT value of <1.93 lived approximately three times longer (54.9 weeks mean survival time) compared with those that did not achieve a cLBT value below this “complete remission” threshold . Furthermore there was a group of dogs which did achieve complete remission by cLBT and also achieved very low cLBT values <0.83 which survived 62.5±11.4.
The test, therefore, demonstrates potential to assist in monitoring treatment of canine lymphoma.
1I. Alexandrakis, R. Tuli, S. C. Ractliffe, S. W. Tappin, R. D. Foale, A. Roos and K. J. Slater. Utility of a multiple serum biomarker test to monitor remission status and relapse in dogs with lymphoma undergoing treatment with chemotherapy. Veterinary and Comparative Oncology. Article first published online: 15 OCT 2014 | DOI: 10.1111/vco.12123.