Should my father-in-law sue for medical malpractice after his surgeon failed to perform routine tests and has now been diagnosed with Stage 4 cancer?

After double hip replacement surgery 2+ years ago, my fater-in-law experienced issues with his prostate and urination issues. He was examined and treated at a local practice in upper WI. Eventually surgery was performed on his prostate to relieve his inability to urinate on his own. On May 30, 2013, after 10 months of increasing and excruciating pain, he contacted and was seen at the Mayo clinic in Rochester, MN. The pain that he had been experiencing in his hip was not a result of the hip replacement as he originally thought, but rather because of a malignant tumor that turned out to have originated from his prostate (bone scans and multiple tests revealed the source at Mayo). Not only did he have the tumor in his hip, but the cancer was found in his ribs, spine, shoulders and other bones throughout his body. The doctors at Mayo and his Oncologists are amazed that the local doctor that performed the original surgery on his prostate never conducted a biopsy before surgery.