Today I’d like to write quickly about one case that was presented at urology multidisciplinary team (MDT) for discussion.
Patient was in his 60s, diagnosed prostate adenocarcinoma T3a (extracapsular extension) Gleason score 8 (4+4) and initial PSA of 45. MRI also noted single left internal iliac lymph node measuring 2 x 1cm with loss of fatty hilum suggestive of malignant.
For localised prostate cancer, risk stratifications to low, intermediate and high risk prostate cancer is the first step to guide management and treatment of localised prostate cancer. Risk stratification uses Gleason score, T staging and initial PSA.
Like most MDT, the discussion will went off topic awhile to have another sub-discussion, which is actually good to stimulate learnings and sharing of expertise.
One urologist mentioned that MRI prostate is ‘not fully’ dependable for staging. That’s why some T3 prostate cancer (extracapsular extension) cases were staged at lower T2 and underwent radical prostatectomy (surgery).
He was right partially.
The standard of care for locally advanced prostate cancer :
- Neoadjuvant androgen deprivation therapy (ADT)
- Followed by radical radiotherapy concurrent with ADT
- Then continue adjuvant ADT for another 2 years.
In general, I do believe MRI prostate is dependable, especially when it’s reported by an experienced radiologist.
Also, the onus is on us to understand in detailed the sensitivity and specificity of MRI prostate in detecting extracapsular extension. Does MRI prostate has
- High sensitivity to detect extracapsular extension? or
- High specificity to detect prostate cancer without extracapsular extension?
Sensitivity and specificity for detection of prostate cancer with MRI prostate (M de Rooij, 2016)
- Extracapsular extension (T3a): 57% and 91%, respectively
- Seminal vesicle invasion (T3b): 58% and 96%
- Overall detection of stage T3 prostate cancer: 61% and 88%
It means that MRI prostate is able to detect accurately only 57% of patients WITH extracapsular extension but has higher accuracy around 91% to detect patients WITHOUT extracapsular extension.
A negative detection of T3 prostate cancer with MRI prostate is more reassuring that patient is likely stage 2/ T2 if distance metastasis had been ruled out.
However, if a patient MRI prostate was reported as T3a by an experienced radiologist, I still wouldn’t recommend surgery but if it’s reported as no extracapsular extension, it will carry more importance and surgery would be a valid option.