Hello, first, I hope that your husband is continuing to recover from his cancer surgery, and further treatment. My latest abdominal surgery had after 7 days recovery, started numbness in the outer thigh, from hip (insertion of Jackson-Pratt drain) all the way to my knee. Nerves are tricky things.My numbness was caused by the lateral femoral cutaneous nerve. Several things could be occurring - irritation, entrapment, injury, neuropraxia, etc. Most of the time nerve issues resolve with time - months and years. Occasionally, there is an intervention that can release the nerve from entrapment. This has just happened to me, on day 7 after abdominal surgery. Since I have a blood clotting disorder, mine had to be immediately ruled out first. Excess fluids, position on operating table, recovery sleeping positions, etc, can all lead to irritation or pressure on the LPC nerve. if it's possible to change sleeping position, (not for me though), and light waling and stretching, to repreposition muscles and nerves and redistribute post-opp fluids, especially if you have Jackson-Pratt drains, as i do. Massage, warm bath or compresses, and wrapping with light compression fabric, or shorts, should help desensitize the constant reminder of numbness. I am wearing an abdominal binder, but also added athletic compression shorts to wear under regular clothing. This helps tremendously with the pins & needles and numbness that is accentuated with touch. I do hope his symptoms have improved.