Benign Prostatic Hyperplasia (BPH): Given the patient's age and PSA levels (total PSA of 1.2 ng/mL and free PSA of 14%), BPH is a common condition in older men that can cause elevated PSA levels, although the percentage of free PSA is within a range that suggests a low probability of cancer.

Prostatitis: This condition can also cause elevated PSA levels and is a common issue in men. The percentage of free PSA is not definitive for cancer, leaving prostatitis as a possible diagnosis.
Prostate Cancer (Low Risk): Although the probability of cancer based on the PSA and free PSA percentages is relatively low (estimated around 1% for PSA levels 0-2.5 ng/mL), it cannot be entirely ruled out without further testing, such as a biopsy.

High-Grade Prostate Cancer: Despite the low probability based on PSA levels, missing a high-grade prostate cancer could be devastating. Therefore, any elevation in PSA, even if slight, warrants careful consideration and possibly further investigation, especially in the context of other risk factors (family history, ethnicity, etc.).
Other Malignancies: Although less likely, other malignancies (e.g., metastatic cancer to the prostate) could potentially cause elevated PSA levels. These would be rare but critical not to miss.

Prostate Sarcoma or Other Rare Tumors: These are exceedingly rare but could present with elevated PSA levels. The diagnosis would typically require biopsy and histological examination.
PSA-Elevating Medications or Conditions: Certain medications and conditions can elevate PSA levels. While rare, these should be considered in the differential diagnosis, especially if other explanations are not found.