Sacrifice
The theme of sacrifice is seen in Dr. Bearing and in her relationship with Dr. Kelekian. Bearing has given her life to researching the Holy Sonnets of Donne. She has become the foremost scholar on his work. We are subtly given the details as to her sacrifice when she is asked her personal history, she has never married, never had children and has no living relatives that are close enough to her to visit. Dr. Kelekian is also a man who has dedicated his life to the study of oncology, and we see the connection in their relationship as they enjoy the effort that they have put in in order to have gained such excellence in their fields.
Death
Vivian's story is about the final days of her life. We are told by her at the beginning of the play that she knows she will die by the time the curtain closes. Thus, these moments in her life become the dramatization of one's life's work and the reality of death bearing down and scrutinizing the life she has lived, and sacrificed for.
Sterility in the Medical Community
Jason represents the primary antagonist that sparks this theme. He is set out to be a world-class researcher, not to save patients. We see how his bedside manner has very little tact, and in a classless action at the end of the play we watch as he attempts to resuscitate Vivian when she is a DNR as to him she is "research."