ONE OF THESE is not real. Can you tell which?"

So begins Susan Miller’s My Left Breast, an Obie Award–winning one-woman play about the writer’s struggle with — and ultimate triumph over — breast cancer. Miller, whose other work includes Nasty Rumors and Final Remarks (also an Obie winner), received the Blackburn Prize for best play written about a woman in the English language for Breast, which she also performs.

And she’ll perform it in Boston on April 11, in a partnership between the New Repertory Theatre and the Wellness Community. At the end of the performance, she’ll do what she always does as the lights begin to dim: she’ll unbutton her shirt to reveal the scar from her mastectomy. But although it’s a powerful moment, Miller says exposing herself physically is just one of the ways that My Left Breast seeks to unite people in their common — or uncommon — experiences with life transitions.

Q: Why’d you originally decide to write a play about your experiences with breast cancer?

A: It didn’t come from wanting so much to chronicle anything. It was just — there was a period of time when a few themes coalesced, and I didn’t want to write anything that didn’t have some kind of literary metaphor and that also didn’t resonate in a much broader way, for myself and for an audience. So it was a time of turning a certain age, of my son turning a certain age, the end of a relationship, and suddenly I felt like I was kind of in the world again, new, almost kind of raw, and it just forced me to look at things in a new way. And so when these things came together, and I was able to also have a sense of humor and irony, then I was able to write about "it," because it wasn’t just about "it."

Q: How do you make such a personal experience interesting to a diverse audience?

A: Well, you know, it’s turned out to be incredibly successful, and also being performed by other people all over the place. I think the key, really, is in the humanity and access to somebody’s flaws and relationships, so that any member of the audience, whether it’s a man or a woman or a young person, can access some part of it for him- or herself. People deal with shifts in their lives, and I think are very interested in how other people deal with them. So I think that’s the way in.

Q: How was the process of writing this play different from the process of writing your other plays?

A: It was different in a sense because it came out in a certain prose form, and because I knew I was going to perform it. So in that sense, in the sense that I wasn’t moving a lot of different characters around, it was different. On the one hand, there was a freedom, but also an awareness that this is entertainment; this has to speak to people.

Q: How do you feel about the comparisons that have been made between My Left Breast and Wit? Do you think those are fair?

A: I think it’s natural for people to ... both plays are written by women, the central character in that piece dies, and I have to say, I know this is going to sound strange, but in the audience when I went to see Wit, the same sort of absolute connection that I find with people in my audiences existed, and people had come back to see the play many times, and that has happened with me as well, but the difference in Wit is that her personal relationships weren’t explored; she was a character without any; that was part of who she was. And this is what’s going to sound strange: I think, because she dies, we are more free, we are allowed, to project on her. We don’t have to get into her messy life, or disapprove of any of it, or say, "Well, I wouldn’t do that." And also, I think you see the character coming to grips with that, which is of course the most extreme thing we all have to deal with in our lives. In my piece, I’m saying, "Here I am, flaws and all, and I’m here as long as I can be, continuing."

Q: How long have you been cancer-free?

A: Twenty-one years. I’m knocking wood here.

Q: Is it something you think of every day?

A: No. No. I think in the beginning, of course I did, when I was younger and so worried about my son, really, and wanting so much to be with him and be well for him and have him in my life. Maybe I’m fortunate — I mean, I am fortunate, in that I was able to have health, and of course think about other things. It’s not that I’m cavalier about it.

Q: Why is it important for you to show your scar to the audience?

A: Well, first let me say that the play is as powerful without that moment — and I know this because I’ve seen someone perform it in France, and I know that the performer in this little touring company in Canada doesn’t have breast cancer — so there’s an alternative to that, in which the lights just go dim as someone starts to unbutton their blouse, or they don’t even, and you can omit the line, "I’m going to show you my scar." In the beginning, I felt several different ways about it, and didn’t know what I would ultimately do. First of all, it’s part of me. You know, I was standing one day in a bank, and I saw somebody without an arm, or with a prosthetic arm. There was also a woman in there who was blind. And there was me. With my clothes on. And no one knew what my scar was, or what missing part I had, or anything. And I just thought, how interesting that we all walk around with these [scars], whether they’re emotional or physical. So it evolved. I do it. I’ve always felt that if it didn’t feel right, I wouldn’t do it. I also don’t surprise people with it; I don’t think that’s right. It’s not about that. I’m not trying to shock anybody.

Q: In the course of performing this play, what are some of the most memorable interactions you’ve had with the audience, or responses from the audience?

A: You know, I’ve always wished that I had kept a complete journal and a tape-recorded session, because I can’t tell you what people have given me, just by speaking, just by telling their stories, just by their relief, their release, their laughter. One favorite thing of mine was actually a young man who was in the audience in Texas, and afterwards he came up to me and said, "You rocked." I just loved that! And there have been men — and I think I’m very, very touched by them — who have either the experience with their wives, or a mother, or a friend. One woman said, "My husband still loves me; when will I feel good again? When will I feel that I look good again, or I look beautiful again? He thinks I am, but I look in the mirror and I see a little girl." We each put ourselves in the other’s hands, for a brief period of time, and it yields something that I can’t even describe, but it makes it all worth it for me.

Q: Eve Ensler got everybody talking about the vagina, with The Vagina Monologues; do you feel it’s equally important that people should be talking about breasts?

A: I know Eve — Eve is a friend. I think [the breast] has been explored in ways that talking about vaginas has not. Also, my piece isn’t based on interviews with people [the way The Vagina Monologues is]. I think, yeah, had I interviewed people [about breasts], or if someone else would interview people, you would find a wealth of material. But I haven’t really thought about it that way. I think Eve should take me on the road with her.

Q: Do you have any particular thoughts on breast implants?

A: I think as long as they’re proved to be safe, women should do whatever makes them comfortable. When this happened to me, it was very new, the idea of reconstruction, and my doctor didn’t want me to do that. And then I didn’t want to have another surgery. I really am for whatever will make people feel better, in terms of implants. Although, the whole thing about enlarging breasts is nuts!

Q: Talk to me about your right breast.

A: Well. I’m glad I have it! Yeah, I’m quite happy to have it.

Q: Does your relationship to one breast change when you lose the other one to breast cancer?

A: Well, there are a couple of levels to answer this question on. First, I think you still have sensitivity erotically actually in both areas. See, what happens, too, is there’s the shock to the system: you have cancer. Jesus. And the main thing is: treat that, I want to be well, I want to live. Now, people who have had one breast removed — I noticed Linda Ellerbee had a double mastectomy, and she is on the air, and she doesn’t wear any prosthesis. She usually wears little black shirts, and it’s great. So part of the thing is, when you have one breast, it’s this constant thing, the imbalance. Do I go out and not care if people look at me? Or do I go out and wear the phony breast, the prosthesis? Just so it’s not an issue. These things I think women do grapple with. I was at a party once, and Isaac Mizrahi was there, the designer, and he’s a funny guy, and I started talking to him, and I said, "You guys should really design a line for women who’ve had a mastectomy." And he looked at me, and I said, "So that they didn’t have to wear anything, so that it was sort of asymmetrical. Well, I’m not the designer," I said, "but maybe you could come up with something so that it would be elegant or sexy or funky. There are so many, many, many women who have had this now."

Q: How did he respond?

A: He thought it was very interesting. He did. I don’t know that he came up with a line! But it’s really something to think about, because of the numbers of women.

Susan Miller will perform My Left Breast at the Copley Theatre, in Boston, on April 11, at 7:30 p.m. Call (617) 332-1646. Tamara Wieder can be reached at twieder[a]phx.com