251P - LDH isozyme as a prognostic factor for patients with metastatic clear cell renal cell carcinoma (mCRCC)

Background

LDH isozyme is a tetramer of two subunits, H chain and M chain, and is present in all living tissue. Five types of molecular forms characterize the LDH pattern, and tumor tissues relatively consist LDH-4 and LDH-5, composed with a high ratio of the M chain, compared to normal tissues. This study analyzed the association between LDH isozyme and prognosis of mCRCC after nephrectomy.

Methods

mCRCC patients initially diagnosed M0 disease between 2012 and 2016 were retrospectively reviewed. LDH isozyme values before operation and at time of metastasis were checked. Isozyme patterns were classified into 6 types, LDH 1-5 dominant and common type, according to the most composed molecular form.

Results

38 patients were identified. Median age was 65 years old (36-87). pT1 was seen in 3 cases, pT2 in 4, pT3 in 27, and pT4 in 4. Pathological grade 2 were 9 cases, G3 in 21, and G4 in 8. As for the IMDC risk, favourable was 2 cases (5%), intermediate in 26 (68%) and poor in 10 (26%). Median LDH was 163 IU/L (113-317), and isozyme dominant pattern were as follows: LDH-2 in 9 cases (24%), LDH-3 in 6 (16%), LDH-4 in 4, LDH-5 in 11. 8 cases were common type, and no cases showed LDH-1 dominant. Median time from surgery to recurrence was 10 months (1-104), median follow-up period after recurrence was 18 months (4-72). 16 deaths occurred. No significant correlation was seen between pre-operative LDH isozyme pattern and pathological grade or pT stage. Pre-operative LDH isozyme did not correlate with time to recurrence (p=0.7420). Median OS for LDH-4 dominant at the time of metastasis was 10.9 months, significantly shorter than other isozyme types (P=0.0134).

Conclusions

LDH-4 dominant isozyme pattern at time of recurrence has a short OS, proposing as a prognostic predictor in mRCC.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

Hayato Takeda.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.