As if confined in a sinister maze, cancer patients often discover that some routes lead to forking branches. It may be impossible to find a way through the bewildering medical labyrinth without feeling lost. My oncologist Dr. Matei, pointing out treatment paths, tells me to choose: “It’s up to you,” she says.

When I had to decide between resuming chemotherapy or entering a Phase I clinical trial, Dr. Matei outlined the pros and cons. She realized that I wanted to participate responsibly in selecting a course that would affect me profoundly. But my ignorance of complex medical protocols led to fearful qualms as I tried to make an informed decision about the benefits and perils of the options.

In part because of the patient empowerment movement, in part because of the changing array of available therapies, a series of problematic choices confront people dealing with cancer. These alternatives must usually be considered under circumstances that are fraught with urgency and anxiety about outcomes.

A colleague with prostate cancer was tormented for months by conflicting advice from the specialists he consulted: Would surgery or radiation pose a greater threat of incontinence and impotence? Breast cancer patients who are offered a lumpectomy with radiation or a mastectomy with chemotherapy may find themselves agonizing over current research as they consider the statistical outcomes and side effects of treatment for their particular tumor type. Then there’s the vexed issue of reconstruction.

Debates that swirled around the actress Angelina Jolie prove how fraught decision making can be for young adults who do not have but might develop cancer. If one tests positive for a genetic mutation that raises the probability of breast and ovarian cancers, is it better to wait and monitor with surveillance or to opt for preventive surgery? Not everyone has the privilege of making such a decision, but it rarely feels like a privilege.

Although Ms.Jolie had double mastectomies, breasts can be more easily screened than ovaries, which produce more deadly cancers. The journalist Masha Gessen, who made the same decision as Ms. Jolie, lists the side effects of the surgically induced menopause that follows an oophorectomy: “risk of heart disease, high blood pressure, osteoporosis, cognitive problems and depression — as well as inelastic skin and weight gain.” For younger women, infertility must be added.

But there is no reliable detection tool for ovarian cancer. And doctors specializing in BRCA mutations disagree about whether removal of the ovaries and the fallopian tubes or a complete hysterectomy should be recommended.

Because waiting and monitoring can produce false negatives, not to mention nerve-racking uncertainty, and because prophylactic surgery can go terribly wrong, the alternatives put me in mind of my parents’ phrase: “alle beide stinken,” meaning “all of them stink.”

A former graduate student with liver metastases was offered two ways to deal with a stomach swollen by ascites, the accumulation of fluid in the abdominal cavity produced by cancer cells. She could continue going to a hospital once a week to have it drained or opt for peritoneal tubes, connected to an external bottle, which would have meant fewer hospital trips and smaller amounts of fluid withdrawn less painfully. But they might result in perforation, infection, leakage or blockage. Even though she was exhausted and depressed — hardly the ideal state in which to make a decision — it was up to her.

Living With Cancer

Susan Gubar writes about life with ovarian cancer.

Though my student was receptive to palliative aids, she had already made the most difficult decision cancer patients confront, one which can generate formidable tensions in any family. The determination to forgo further curative treatment may ignite distress in relatives desperate to maintain the lives of their loved ones.

In this context, as in the others, I doubt that most people would want to return to the paternalism of the past when physicians monopolized medical decision making. Yet many of us need the guidance of our doctors whose training and experience make them better able to calculate the brutal risks.

The playwright Eve Ensler certainly did, and she asked her doctor why he recommended radiation that would make it difficult for her to eat or excrete. According to her memoir, “In the Body of the World,” he said: “It’s up to you. Only you can decide.” When she then inquired, “What would you do if this were your body?” he responded, “Can’t say.” After she pressed again, he recited “the mantra of the end of the world.”

“We like to throw everything at it,” he said. “That’s all we know how to do.”

Happily, I cannot imagine those words coming out of the mouth of my oncologist. While appreciating my values and priorities, Dr. Matei uses her medical expertise not “to throw everything at it,” but to counsel me. We shared responsibility for making what turned out to be a good decision in favor of the Phase I trial.

Cancer patients and physicians should engage in serious conversations. I always bring my partner or a friend to such a session so the discussions can continue afterward with someone who has listened to the choices, their rationales and their potential consequences.

Are there other diseases that require this stressful level of patient decision making? Given the angst such choices generate, I understand why some people refuse them and reject standard care in favor of daily quarts of carrot juice — not my decision, but it’s up to them. Whether or not carrots are curative, good vision in a savage wood is what we all need.

Susan Gubar is a distinguished emerita professor of English at Indiana University and the author of “Memoir of a Debulked Woman,” which explores her experience with ovarian cancer.