Quoted in People, 26 Dec. 1977. Although now associated with Tomlin, this saying appears anonymously in Robert Reisner, Graffiti (1971), in the form "Remember, even if you win the rat race - you're still a rat." Rosalie Maggio, in New Beacon Book of Quotations by Women, states that William Sloane Coffin said "Even if you win the rat-race, you're still a rat" as a chaplain at Williams College or Yale University in the 1950s or 1960s.
Jon Kabat-Zinn (2013). “Full Catastrophe Living (Revised Edition): Using the Wisdom of Your Body and Mind to Face Stress, Pain, and Illness”, p.74, Bantam