Table 1.

Summary of themes and supporting quotes from the data of 29 patients with lung or colorectal cancer

Overarching theme		Subtheme	Supporting quotes
Pre-symptom perception			1. I didn’t really feel any different, so I didn’t go to the GP. (CQ18, 69-year-old female with colorectal cancer); 2. I wasn’t ‘ill’ ill to go to the doctors. (CQ17, 69-year-old female with colorectal cancer); 3. I didn’t really think a great deal about it. I had a bit of a cough but nothing bad, you know. (CQ14, 58-year-old male with lung cancer)
Symptom perception	Arguments/rationales underlying alternative explanations	No pain, no problem	4. No pain, no chest pain, or anything, no pain anywhere, just this [fatigue], so I just attributed it to being tired, if you like. (CQ4, 56-year-old male with lung cancer); 5. No it wasn’t a pain; I think if I’d have been in pain I would have gone to the doctors earlier. (CQ25, 73-year-old female with colorectal cancer)
		Inconsistency of symptoms	6. It [bowel movements] was every now and then, like, you know, so that’s why I didn’t put it down to anything serious, sort of, thing. (CQ1, 74-year-old male with colorectal cancer)
		Lack of ‘obvious’ symptoms	7. …there was nothing obvious, there was no blood or you know obvious blood in the toilet or anything that would make me… (CQ15, 67-year-old female with colorectal cancer)
	Types of alternative explanation adopted by patients	Comorbidity/link to previous illnesses/side effect of medication	8. Yeah, well, I’m asthmatic, see, anyway, because you have a tendency to cough a bit more, being asthmatic. (CQ19, 69-year-old male with lung cancer); 9. I suppose really, I’d hear so much from different people, that you get side effects with Statins and I know lots of people who just won’t take them because of these side effects. I’d been on one, Atorvastatin … and then another GP, she changed me to Simvastatin and it was a while after when I got these sensations [bowel movements] you know, that; and I thought ooh, you know, is it because I’m taking these Statins, the different ones, and it went on from there, you know. (CQ25, 73-year-old female with colorectal cancer); 10. So I’ve been over 12 months now that I haven’t smoked, but I smoked for a long time [yeah]. So, well, with the asthma and the smoking, I put that down to the short- windedness. (CQ19, 69-year-old male with lung cancer)
		Benign explanation available	11. If I’d had a big meal like a Sunday dinner or something, …I always needed to go to the toilet not long after. And I did get a bit of a pain in my tummy then but I just thought it was down to eating too much. (CQ22, 59-year-old female with colorectal cancer); 12. Yeah, and it [rectal bleeding] stopped and it was probably a slight cut, maybe, an abrasion of some form for whatever reason, whether it was sport or anything. I played a lot of sport and stuff. So yeah, that’s where you get to dismiss it a little more. (CQ8, 44-year-old male with colorectal cancer); 13. …to my wife, ‘I think I’ve coughed some blood up’. Well, I said to them at work, ‘I’m sure I’ve coughed some blood up’. There again, I said, ‘I was drinking red wine last night, it could be that,’ [okay] you know, you just passed it off. I did it a couple of times then it went away. (CQ19, 69-year-old male with lung cancer)
		Old age	14. I just put it down to being on the engine, just driving, just standing there pulling levers, and not doing what I’d done for 40 or 50 years. I was running up and down, you know, at the side of the trains, sort of, thing, doing the shunting. So I thought, ‘I’m getting a bit old here [laughs]. I’m losing it a bit, like, with just being stuck in one position on the engine, just doing the levering’. So I just put it down to that. (CQ1, 74-year-old male with colorectal cancer); 15. When I asked the patient about the first indication that something was wrong, he told me that he had experienced breathlessness and a lack of energy while digging in the garden. However, the patient attributed this to ageing and did not discuss the symptom with anyone. (Notes from interview with CQ7, 72-year-old male with lung cancer)
	Validation/provision of alternative explanations by significant others		16. But everybody was saying at that time they’d got a cough, the people we were with at [place], he was cough, cough, cough, all the while. He’s been going to the doctors ever since and they can’t find anything wrong with him. (CQ5, 71-year-old male with lung cancer); 17. People say, ‘Oh, it’s just as you’re getting older’. Everybody puts it down to age. (CQ17, 69-year-old female with colorectal cancer)
Triggers to action	Alternative explanation(s) no longer viable	Ineffectiveness of self- medication	18. I think it [constipation] was getting on for about 10 days. I was getting quite worried because I’d tried all over-the-counter medication from the chemist, but nothing seemed to help at all, that’s why I went to the GP. (CQ27, 74-year-old female with colorectal cancer); 19. …because being a man, you don’t go to the doctors [laughs]. You suffer it out, you know, which I did to a degree, and I was just taking cough medicines and things like that. But there was no relief. (CQ4, 56-year-old male with lung cancer)
		Persistence of symptoms	20. At first I thought because, you know, I’d had it a bit earlier in the year, and it had gone away, I thought, ‘Maybe it’s just some sort of tummy bug or something like that, but when it got to the 1st of June, and I thought, ‘It’s not gone away. I need to make a doctor’s appointment,’ and so that was when I went to see my GP. (CQ20, 33-year-old male with colorectal cancer); 21. This cough was different. I could not just stop coughing. And I couldn’t sleep. I’d get down on my back, cough and cough and cough. So I thought, ‘Right, I’ll go see a doctor’. (CQ23, 63-year-old male with lung cancer)
		Progression of symptoms	22. As I said, when it become heavy blood, that was whoa, this is a totally different ball game now, this is something majorly wrong. (CQ3, 63-year-old male with colorectal cancer); 23. And I thought, ‘I know there’s something not right,’ and it was getting worse, actually. This coughing got worse. The aches and pains got worse. (CQ23, 63-year-old male with lung cancer)
		Loss of function	24. I just couldn’t breathe, and my job is plastering, which is all physical work. (CQ14, 58-year-old male with lung cancer)
		Pressure from others	25. Yes they [family] were concerned. They were ringing all the time. …When my sister came from [place], she came on 1st March and she said ‘you have to get to a doctor, you need to go into hospital regardless of what the doctor says’. (CQ21, 84-year-old male with colorectal cancer); 26. She [patient’s wife] was concerned, initially, because I was coughing, and it didn’t seem to be getting any better, it would get worse. So that was what concerned her in the first place, which, in a sense, was a good thing, because me being a man [laughs], I would have left it until I was on death’s door to go to the doctor. (CQ4, 56-year-old male with lung cancer)
	Perceptions of risk	Awareness of risk	27. P: I had to go and get it seen to because I knew I’d been a heavy smoker didn’t I, so…? I: Right, so you had that sort of knowledge did you in your mind that…? P: Yeah, yeah. In your mind that you’ve asked for it in a way, haven’t you? Although when we were younger it wasn’t considered to be asking for it, was it? It was considered the thing to do. (CQ5, 71-year-old male with lung cancer)
		Patient fears they may have cancer	28. Yeah, I was quite convinced it was a tumour by the time I went to the doctors, I think the polyp theory had gone by then, the blood was too much, it was solid, it was congealed. (CQ3, 63-year-old male with colorectal cancer); 29. I knew myself it was more than—he did mention COPD first one. But I’ve got a friend with COPD and my symptoms didn’t match hers. (CQ30, 63-year-old female with lung cancer)
	Awareness of public health campaigns		30. And there was an advert on the television at the time as well that kept coming on all the time that made me keep thinking about it as well. (CQ22, 59-year-old female with colorectal cancer); 31. And there was a big advertising campaign on about bowel cancer. Two weeks went by and the referral time is supposed to be two weeks, two weeks went by and I haven’t heard anything and I phoned up and he got the receptionist to say he was sorry, he didn’t think I thought it was important. (CQ3, 63-year-old male with colorectal cancer); 32. I didn’t have, like, a cough like when you see the adverts, you know, a cough all the time. (CQ14, 58-year-old male with lung cancer)
Endorsement or refutation of alternative explanations by HCPs			33. I was getting breathless, I was getting breathless. But as I say again I was putting it all down to my asthma…The doctors were saying ‘take your blue inhaler, your blue thing more often’. (CQ24, 61-year- old female with lung cancer); 34. …so I went to the doctors, and I didn’t see my regular one; it was just a locum doctor that was there and his diagnosis was haemorrhoids, but he referred me to [name of hospital]. (CQ20, 33-year-old male with colorectal cancer); 35. Yeah I went along and she just said well you’d better go for an X-ray, and that was about it really. …And I think I went on the Friday, she’d got the results on the Tuesday I think. (CQ5, 71-year-old male with lung cancer)