Tower, I took 7 months' sick leave (I got full pay for that!) during which 7 weeks were used for treatment: concurrent chemo and radiation therapy. Before I resumed my job officially, I took a 3 week trial working just in the morning doing some paper reading and light administration work. This was an adjustment period suggested by my doctor to test if I were really physically and mentally fit for work. When I was ready, the doctor didn't give me any more sick leave and I resumed my full time job until now working from 8 a.m. to 6 p.m. Energy level increased gradually and I am now as productive as I was before. This is my experience and there is no fixed and fast rule on how soon you can return to work. It depends very much on the job nature,and your reaction to the treatment, etc. Stay positive and be patient.
Karen.