Table 2.

Study Characteristics and Major Findings

Article author, year	Study design and data collection mode	Population and sample size and country	Clinical Endpoint	Key measures	Major findings
Bridges et al. (2012) [10]	Quantitative (cross-sectional online survey) Conjoint analysis methodology to explore trade-off preferences	Advanced non-small cell lung cancer patients (N = 89) UK	PFS	Dependent variables: Treatment preferences Benefits that patients judged sufficient to compensate for the risks associated with therapy for advanced NSCLC NCSLC patients’ stated treatment preferences	Patients’ understanding of clinical endpoint concepts and treatment intent Patients indicated in pretest interviews that they understood the meaning of PFS as time to disease progression. However, they were unaware of the difference between PFS and OS. Patients’ perceptions of clinical endpoint importance and perceived tradeoffs Patients ranked the relative importance of PFS (4, 5, and 7 months) along with a variety of disease symptoms of increasing severity. Having an improvement in disease symptoms with 7 months PFS was most important, followed by 5 months, and 4 months. As severity of treatment risks increased, patients’ preferences for these treatments diminished.
Catt et al. (2015) [18] [conference abstract]	Qualitative (semi-structured individual interviews)	Patients with metastatic cancer (N = 11) UK	PFS	Dependent variables: Patients’ familiarity with the phrase “progression free survival” Patients’ beliefs about the aims and benefits of new treatment for advanced cancer.	Patients’ awareness of clinical endpoint concepts Only one patient (9%) recalled the phrase PFS used in clinical consultations and four (36%) had no idea what this term meant. Patients’ understanding of clinical endpoint concepts and treatment intent Four patients (36%) incorrectly believed the therapeutic aim of further treatment was to extend survival. 8 (73%) believed the aim of the treatment was to slow the cancer. Four patients (36%) who had not yet begun treatment believed the benefits of their new treatment included extending life.
Craft et al. (2005) [11]	Quantitative (longitudinal in-person survey)	Patients with advanced cancer receiving palliative therapies (N = 181) Australia	N/A	Dependent variables: Knowledge of treatment intent (treatment wasn’t curative, treatment was intended to improve QOL or control illness) Independent variables: Age, marital status, education, country of birth, place of residence, occupation, cancer type, type of therapy, course of illness, site of disease, time to death, psychosocial classification	Patients’ understanding of clinical endpoint concepts and treatment intent Less than half (47.4%) of participants correctly understood that their treatment was not curative. Responses to this question were measured at week 1 and week 12. The number of patients that reported that their treatment was curative at week 1 was higher than the number at week 12. Nearly half of those undergoing chemotherapy thought the treatment goal was curative versus 28% receiving supportive care. Non-ambulatory patients and patients closer to death were more likely than others to understand the goal of treatment was not curative.
Fallowfield et al. (2017) [12]	Mixed-method (cross-sectional survey and in-person or telephone interviews)	Patients diagnosed with metastatic cancer, with a predicted life expectancy of at least 6 months, who were about to commence treatment with prescription drugs that demonstrated only progression-free survival (PFS) or modest overall survival (OS) benefits at the time the study commenced (N = 90) Oncologists who prescribed drugs that demonstrated only PFS or modest OS benefits at the time the study commenced (N = 32) UK	PFS	Dependent variables: Patients’ understanding and expectations of the phrase PFS Patients’ understanding of treatment aims The benefits patients expected from treatment Patients’ answers to time-trade-off questions	Patients’ awareness of clinical endpoint concepts During conversations with the patient about the cancer treatment, 99% of oncologists reported discussing the aims of treatment, but only 28% (n = 25) of oncologists reported explicitly using the terms “progression-free survival” or “progression-free interval.” When asked, only 4 of 90 patients recalled its use. Patients’ understanding of clinical endpoint concepts and treatment intent Understanding of the term “PFS” was mixed. 57% (N = 51) of patients reported they had no idea or were unclear about what PFS meant. 32% (N = 29) thought it was about controlling cancer (which was somewhat in line with PFS definition), and 11% (N = 10) thought it was about extending life. The majority (92%) (N = 83) believed that an aim of their treatment was to slow or stop the cancer. 50% (N = 45) also believed that this meant living longer. 39% (N = 35) said living longer was the most important aim of treatment, and 62% (N = 56) thought that their understanding of treatment aims would be achieved. When asked about benefits they expected from treatment, 86% (N = 77) believed it would keep the cancer under control, 54% (N = 49) believed it would make them feel better, and 39% (N = 35) believed it would help them to live longer. Patients’ perceptions of clinical endpoint importance and perceived tradeoffs In a time-trade-off analysis, patients were significantly less likely to feel that the benefit of controlling the cancer was worthwhile as the severity of the side effects increased.
González et al. (2016) [19] [conference abstract]	Quantitative (cross-sectional online survey) Discrete choice experiment (DCE)	Patients with a self-reported physician diagnosis of renal cell carcinoma (N = 201) US	PFS OS	Dependent variables: Patients’ perceptions of and preference weights for PFS and OS efficacy measures.	Patients’ perceptions of clinical endpoint importance and perceived tradeoffs Perceptions of a treatment’s PFS was not correlated with perceptions of long-term and uncertain efficacy outcomes (i.e., survival). When selecting a preferred treatment, the most important attribute to patients was long-term survival, followed by PFS, treatment cost, adverse events, and route and frequency of administration. Patients tended to focus on improved chances of long-term survival and largely discounted PFS as a measure of treatment efficacy. Among patients with metastatic disease, a 2.5-month increase in PFS was rated as important as a 10% increase in survival.
Jenkins et al. (2018) [13]	Mixed-method (cross-sectional survey and in-person or telephone interviews) Secondary data analysis	Patients diagnosed with metastatic cancer, with a predicted life expectancy of at least 6 months, who were about to commence treatment with prescription drugs that demonstrated only PFS or modest OS benefits at the time the study commenced (N = 90) UK	PFS	Dependent variables: (measured at baseline and 6 weeks) Patients’ perceptions of the trade-off between PFS and quality of life Independent variables: Type of cancer patient	Patients’ perceptions of clinical endpoint importance and perceived tradeoffs As the severity of the possible side effects increased, patients were less likely to indicate that the benefit of controlling the cancer (PFS) would be worthwhile (95% of patients indicated controlling cancer was worth it if they experienced Grade I side effects vs. 44% for Grade III side effects). This pattern was found at baseline and at 6 weeks on treatment, and the same pattern was found for patients with lung, melanoma, and breast cancer. As side effect severity increased, patients wanted the treatment to control the cancer for longer to make the treatment worthwhile.
Johnson et al. (2015) [14]	Literature review	N/A	N/A	Definitions of curative	Patients’ understanding of clinical endpoint concepts and treatment intent There were a variety of ways in which cancer “cure” was described and differences across physicians, academics and patients were noted. It was much more common for documents from healthcare professionals and academics to use language related to disease progression and survival whereas patients tended to describe “cure” in terms of successful eradication of cancerous cells.
O’Donnell et al. (2018) [20] [conference abstract]	Mixed-method (Structured discrete choice trade-off exercise and in-person interviews)	Ambulatory clinic patients with advanced metastatic cancer (lung, colorectal, or ovarian) who had completed at least 3 months of chemotherapy (N = 20) Canada	PFS OS	Dependent variables: Discrete choice trade-off exercise between treatment options with the same OS but different PFS, treatment time, and toxicity levels.	Patients’ perceptions of clinical endpoint importance and perceived tradeoffs Most participants (85%) (N = 17) chose treatment with shorter treatment time and lower toxicity levels even when PFS was shorter. Two patients (10%) chose treatment with higher toxicity but longer PFS, and one patient (5%) always chose the most aggressive treatment regardless of PFS and toxicity.
Postmus et al. (2018) [15]	Quantitative (cross-sectional online survey) Decision-analysis methodology	Multiple myeloma patients (N = 560) UK	PFS	Dependent variables: Patients’ preference weights for PFS and side effects (ranging from mild to life-threatening) of two hypothetical treatments Patients’ perceptions of the trade-off between PFS and treatment side effects Independent variables: Age, time of diagnosis, employment status, number of previous treatments, number of dependents, current side effects or other health problems, or regular contact with support group	Patients’ perceptions of clinical endpoint importance and perceived tradeoffs The average preference weight given to PFS was higher than the average weight given to severe or life-threatening treatment toxicity or mild or moderate chronic toxicity. The majority of participants (58%) considered increasing the probability of being progression-free for 1 year or longer from 50% to 90% to be more important than simultaneously decreasing the probability of experiencing severe or life-threatening toxicity from 80% to 20% and the probability of experiencing mild or moderate chronic toxicity from 85% to 45%. The amount of weight given to PFS was not associated with age, time of diagnosis, race, employment status, number of previous treatments, number of dependents, current side effects or other health problems, or regular contact with support group.
Protiere et al. (2017) [16]	Mixed-method (Q-sort methodology with quantitative and qualitative components)	N = 146; Cancer patients in remission at 18 months of diagnosis (n = 52) General population (n = 46) Oncologists (n = 27) Healthcare decision-makers (n = 19) Pharmaceutical industry representatives (n = 2) France	PFS OS	Dependent variables: Respondent perceptions of trade-offs between quality of life and length of life for a hypothetical drug for advanced cancer Independent variables: Type of population (health decision-makers, oncologists, cancer patients, general population)	Patients’ perceptions of clinical endpoint importance and perceived tradeoffs 13 patients, 25 general population participants, 18 oncologists, and 16 healthcare decision-makers endorsed the view that quality of life is more important than length of life and that an effective treatment would allow the patient to live a life comparable to their life before the disease. 2 patients and 1 general population participant and 4 oncologists endorsed the viewpoint that a gain in OS or decreasing the risk of disease progression is preferred even if it implies a decrease in quality of life and negative impacts on family, social, and professional life. Healthcare decision makers did not endorse this viewpoint.
Sheik-Yousouf et al. (2010) [21] [conference abstract]	Quantitative (cross-sectional survey)	Patients with metastatic breast cancer (N = 52) and oncologists (N = 28) Canada	PFS, OS, ORR	Dependent variables: Respondents’ perceptions of clinically important endpoints in the treatment of metastatic breast cancer Independent variables: Type of population (oncologist vs. patient)	Patients’ understanding of clinical endpoint concepts and treatment intent Study examined the importance of clinical endpoints/outcomes (OS, PFS, ORR, and QoL) among physicians and patients. The abstract discussed PFS only as a treatment goal from physicians. For patients, the treatment goals were OS, ORR, and QoL. 88% of patients believed the primary goal of their treatment was to prolong life; 63% also believed slowing tumor growth was a goal of treatment. 50% of patients indicated that improving symptoms and pain (i.e., QoL) were important treatment goals. 54% of patients and 52% of oncologists said OS was the most important endpoint considered in choosing a specific therapy. 48% of oncologists thought PFS was the most important endpoint and 17% of patients thought shrinking tumor size was the most important endpoint. Oncologists considered much smaller absolute improvements in OS and PFS (2–6 months) as significant enough to adopt therapies, while almost half (46%) of patients thought that a treatment would need to extend their life by at least 12 months to make it worthwhile.
Shimer et al. (2018) [22]	Quantitative (cross-sectional survey)	Patients admitted with acute leukemia (N = 90) and their treating hematologists US	N/A	Dependent variables: Patients’ perceptions of treatment goals, chance of cure, expected survival Independent variables: Population (physicians and patients) Relapse (nonrelapsed, relapsed)	Patients’ understanding of clinical endpoint concepts and treatment intent Most patients (82.2%) and physicians (78.9%) shared a goal of cure. Compared with physician estimates, significantly more non-relapsed (58% vs. 5%) and relapsed (39% vs. 0%) patients reported they had a greater than 80% chance of cure.
Temel et al. (2011) [17]	Quantitative (experimental randomized controlled trial, longitudinal)	Ambulatory patients newly diagnosed with metastatic non-small cell lung cancer (N = 151) US	N/A	Dependent variables: (Measured at 12, 18, and 24 weeks) Effect of early palliative care on longitudinal perceptions of illness understanding Accuracy of patients’ perceptions of prognosis and therapy goals Independent variable: Type of care (standard vs. early palliative)	Patients’ understanding of clinical endpoint concepts and treatment intent Despite having terminal cancer, at baseline 31% (n = 45) reported that their cancer was curable. 33% of participants did not think their cancer was curable, but they did think that the goal of their therapy was to get rid of all their cancer. 97% (n = 138) indicated that a goal of treatment is to help them live longer and 69% (n = 84) reported that a goal of treatment was to get rid of all their cancer. There was a significant (p = .02) positive effect of early palliative care on illness understanding by patients over time: 82.5% of patients assigned to early palliative care either remained or became accurate in the perception that the cancer was not curable compared with 59.6% of patients receiving standard care. Type of care did not significantly affect perceptions of the goals of treatment at any time point; the majority of patients continued to report that an aim of therapy was to get rid of all the cancer. Time of assessment (baseline vs. 12, 18, and 24 weeks) did not significantly affect perceptions that the goal of the treatment was to live longer.

Note. ORR = objective response rate; OS = overall survival; PFS = progression-free survival; QoL = quality of life