**Core Concept**
The T1a stage of adenocarcinoma refers to a non-aggressive, incidental finding of cancer in a small portion of the prostate tissue removed during surgery, often in the context of a transurethral resection of the prostate (TURP) for benign prostatic hyperplasia (BPH). In this scenario, the cancer is not palpable or clinically significant.

**Why the Correct Answer is Right**
The T1a stage of adenocarcinoma is characterized by a small volume of cancer, usually less than 5% of the total prostate tissue, and is often incidentally discovered during histopathological examination of the resected tissue. Since the cancer is non-aggressive and not clinically significant, active treatment is not typically recommended for T1a prostate cancer. The patient's age and the small volume of cancer make it unlikely to cause symptoms or affect the patient's lifespan.

**Why Each Wrong Option is Incorrect**
**Option A:** Endocrine therapy is typically used for more advanced prostate cancer, often in conjunction with other treatments like radiation or chemotherapy.

**Option B:** Radical surgery, such as a radical prostatectomy, is a more aggressive approach usually reserved for clinically significant cancers or those that are causing symptoms.

**Option C:** Hormone therapy is used to treat more advanced prostate cancer by reducing testosterone levels, which can slow cancer growth.

**Clinical Pearl / High-Yield Fact**
For T1a prostate cancer, the risk of recurrence or metastasis is extremely low, and the cancer is often considered a "finding" rather than a disease that requires treatment.

**✓ Correct Answer: D. No further treatment**